Messages for Out of Service Antennas

Id
Name
Cause
Action
005 ACU FAULTS

See example overlay		 This message is caused by a fault in one of the elevation or azimuth motors, or by a circuit breaker fault.
  • Try resetting the ACU from the WYE-MON.
  • Try repointing the Antenna from the AC overlay.
  • If problem won't clear then open a maintenance report.
  • Call Servo based upon severity of problem.  If the emergency stop cannot be set, or if the elevation can not be read, CALL SERVO IMMEDIATELY.
006 OUT-OF-SERVICE ANTENNA NOT AT ZENITH

See example overlay		 An out-of-service antenna is reporting that it is not in the stowed position.  This can be caused by maintenance procedures or something severe like loss of control of the antenna.
  • Check ACU display & WYE-MON for indication of Antenna @ +/-5 degs from Zenith (Panel will be Yellow).
  • If the antenna is not at stow, should be, and will not go there, then CALL SERVO IMMEDIATELY.
  • Write up a maintainance report.
010 WARM DEWAR    (VLA dewar only!)

See example overlay		 A dewar could be warm because of maintenance work, or because of a failure (such as a helium leak or refrigerator failure)
  • Call Cryo, unless the dewar is intentionally warm due to maintenance work.
  • Write up a maintainance report.
020 VERTEX ROOM TEMPERATURE OUT OF RANGE

See example overlay		 The vertex room temperature as monitored in the B-rack is either <17 or >23 degrees C.  This condition will occur if air flow is lost or if the HVAC system has malfunctioned. 
  • Check the B rack temperature from the PS overlay.
  • If the temperature is too cold, open a maintenance report.
  • If the temperature is between 24 and 30 degrees C, open a maintenance report.
  • Watch the temperature to make sure that the condition is static. 
  • If the temperature continues to change, then notify HVAC. 
  • If the B-Rack temperature is above 30 degrees,   Call HVAC immediately and open a maintenance report. The B-Rack must be shut off as soon as possible. At this time, auto shutoff for B-Rack is not available so you must call HVAC or damage may occur to B-Rack electronics.


Messages Indicating Flagging Conditions

Id
Name
Cause
Action
050 SOURCE CHANGE IN PROGRESS The observing schedule has specified a source change. None.
051 SUBREFLECTOR NOT IN POSITION

See example overlay		 Position in Focus/Rotation out by > 10 counts for rotation or > 200 counts for focus.
  • Go to the FR overlay.
  • Command the subreflector to the correct position.
  • Open a maintenance report.
  • Contact Servo or DCS.
052 ANTENNA OFF SOURCE This could be cause by the antenna going through a 360 degree "unwrap", or a 180 degree "over the top" adjustment in azimuth. None.
053 L6 OUT OF LOCK

See example overlay		 One of the L6s is out of lock. 
  • Check L6 overlay to determine which L6 is out of lock (AC or BD).
  • Send the L6 to another frequency then back to the required frequency, using the L6 overlay.  Possible frequencies to try are 2690 MHZ and 4010 MHZ.  This may cause the L6 to lock up again. 
  • If the L6 does not lock, the antenna is considered 1/2 down, with regard to the 3 antenna rule.
  • Open a maintenance report, whether or not the L6 can be made to lock up again
054  L8 OUT OF LOCK

See example overlay		 L8 is out of synchronization.  The L8 modules at the antennas are synchronized with the L8 module in the master LO rack.  This message applies only to L8 modules at the antennas. 
  • Reset the LO system from the LO overlay, and determine if the L8 goes back in to lock.  If the L8 is out of lock, a warning will flash on the LO overlay.
  • If the L8 can not be made to lock, do not use the antenna.
  • Open a maintenance report, whether or not the module goes back in to lock.
055 BE FILTERS SET WRONG

See example overlay		 Backend filters in the T4 are not selected properly. 
  • Select the filters by going to the BB (baseband) overlay.
  • If selecting the filter does not fix the problem then swap the T4.
  • If the T4 swap doesn't fix the problem, notify LO/IF.  The antenna is 1/4 down according to the 3 antenna rule, for each T4 that is down.
  • Open a maintenence report.
056 BACKEND TP OUT OF RANGE

See example overlay		 Total power as monitored in the T5 is out of range.  The acceptable range of total power is 4 - 9 volts. 
  • Check the T5 overlay and check problem.
  • Go to the D racks and check on the T5.
  • Reseat module. If problem persists then replace module.
  • If the above action does not correct the problem, the antenna is 1/4 down for each affected IF.
  • Open a maintenance report.
057 FLAGGED BAD IN IF FILE Operator None.
058 TSYS FLUCTUATIONS

See example overlay		 The synchronous detector voltage is varying rapidly.  May indicate RFI.
  • The IF that is affected is out of service.  The antenna is considered 1/4 down for each IF that is affected, according to the 3 antenna rule.
  • Open a maintenance report and indicate RFI trouble.
059 FIRST LO OUT OF LOCK

See example overlay		 The first LO is out of lock for an observing band that is currently being used.
  • Inspect the FE overlay.
  • Open a maintenance report.


Messages for Operational Issues

ID
Name
Cause
Action
100 L6 IN MANUAL

See example overlay		 The L6 in the antenna was left in manual. 
  • If possible, have someone set the L6 to computer mode.  No further action is necessary.
  • If there is no one available to set the L6 to computer mode, open a maintenance report.
  • Determine which L6 was left in manual from the L6 display.
  • Notify the LO/IF Group.
  • 1/2 of the antenna is considered down according to the 3 antenna rule.
  • Open a maintenance report.
101 ACU IN MANUAL

See example overlay		 ACU computer/local switch has been left in manual position.
  • Call Servo or last group that was on Antenna to set switch in computer position.
  • Do not use the antenna.
  • Open a maintenance report if necessary.
103 FRONT END IN MANUAL

See example overlay		 The F5 module has been left switched to "Local" and cannot be controlled remotely.  Affects all bands.
  • Notify the Front End group.
  • Do not use the antenna.
  • Open a maintenance report if necesary.
110 ANTENNA ID - DCS NUMBER CONFUSION

See example overlay		 Reported Antenna ID does not match assigned ID to DCS in computer file.
  • Check Antennas file.
  • If the file is ok, then open a maintenance report and contact the DCS group.
  • If the file is not ok, correct it.
  • Open a maintenance report.


ACU Related Messages

ID
Name
Cause
Action
200 FAN FAULT 

See example overlay		 The PED room temperature is too high and/or the AC fan is inoperative (no air flow).
  • Notify HVAC.
  • If after hours, have someone prop the door open if possible.
  • Open a maintenance report.
201 EMERGENCY STOP

See example overlay		 E-Stop switch set.
  • If a "local e-stop" shows on the WYE-MON panel, call Servo to investigate.
  • If e-stop has been activated from the WYE-MON, try to release it.  If it won't release from the panel,  notify the DCS group.
  • Open a maintenance report.
202 FIRE DETECTION MALFUNCTION Indicates problem with antenna fire alarm system.
  • Open a maintenance report. 
  • Notify Servo or Electricians.
203 FIELD FAULT

See example overlay		 Indicates a field winding problem with one of the Servo drive motors.
  • If only a single motor is affected, the antenna may be usable.
  • Notify Servo.
  • Open a maintenance report.
204 CIRCUIT BREAKER FAULT

See example overlay
  • 204 only: Az gearbox lube pump pressure low.
  • 204 and 210, or 204 and 214: Tripped CB in Servo drive cabinet.
    		•
    • 204 only - Contact Servo or AAB, CALL OUT IF THE ANTENNA IS NOT POINTED AT ZENITH AND WILL NOT GO THERE.
    • 204 & 210/214 - Contact Servo, CALL OUT IF THE ANTENNA IS NOT POINTED AT ZENITH AND WILL NOT GO THERE.
    • Open a maintenance report.
    205 DRIVE CABINET OVER TEMPERATURE The Servo cabinet has reached its overtemp limit.
    • Stow antenna.
    • If possible, have someone shut off critical power to the drive cabinet, and contact servo.
    • If someone is not available to shut off critical power, call Servo. CALL OUT.
    • Open a maintenance report.
    206 INPUT BREAKER TRIPPED
  • 206 only: AZ/EL encoder heater/blower CB tripped.
  • 206 and servo system unresponsive: 100A CB that feeds power to servo drive cabinet has tripped in power distribution panel.
    		•
    • 206 only - Contact Servo during business hours. 
    • 206 and servo system unresponsive: Contact Servo, CALL OUT IF ANTENNA IS NOT POINTED AT ZENITH.
    • Open a maintenance report.
    207 MOTOR OVER TEMPERATURE

    		 One or more Servo drive motors has reached it's overtemp limit & shut down.
    • Notify Servo.
    • Open a maintenance report.
    208 AZ LIMIT CW

    See example overlay    		 Antenna has reached the physical CW limit of the cable wrap travel region.
    • If in 1st AZ Limit try to back-out using limit override command on the AC overlay.
    • If in 2nd limit, then Servo must be called to release control back to OPS.
    • Try resetting the ACU from the WYE-MON.
    • Try repointing the Antenna from the AC overlay.
    • Open a maintenance report.
    209 AZ LIMIT CCW

    See example overlay    		 Antenna has reached the physical CCW limit of the cable wrap travel region.
    • If in 1st AZ Limit try to back-out using limit override command from the AC overlay.
    • If in 2nd limit, then Servo must be called to release control back to OPS.
    • Try resetting the ACU from the WYE-MON.
    • Try repointing the Antenna from the AC overlay.
    • Open a maintenance report.
    210 AZ MOTOR FAULT

    See example overlay    		 Any one of the following conditions can generate an AZ motor fault:
  • Main field breaker in drive cabinet tripped.
  • #1 or #2 field breaker tripped in drive cabinet.
  • #1 or #2 motor armature breaker tripped in drive cabinet.
  • #1 or #2 electronics ckt breaker tripped in drive cabinet.
  • Brake circuit breaker tripped in drive cabinet.
    		•
    • Try resetting the ACU from the WYE-MON.
    • Try repointing the Antenna from the AC overlay.
    • Notify Servo.
    • Open a maintenance report.
    211 NOT DIGITAL POSITION MODE

    See example overlay    		 ACU has dropped out of pointing mode.
    • Try resetting the ACU from the WYE-MON.
    • Try repointing the Antenna from the AC overlay.
    • If problem doesn not clear open a maintenance report.
    • If no go, call Servo.
    • Open a maintenance report.
    212 EL LIMIT UP

    See example overlay    		 Antenna has reached the physical limit of Elevation UP motion.
    • If in 1st limit, try to back out using the override command.
    • If in 2nd limit then Servo must be called to release control back to OPS.
    • Try resetting the ACU from the WYE-MON.
    • Try repointing the Antenna from the AC overlay.
    • Open a maintenance report.
    213 EL LIMIT DOWN

    See example overlay    		 Antenna has reached the physical limit of Elevation DOWN motion.
    • Use same procedures as Alarm #212.
    • Open a maintenance report.
    214 EL MOTOR FAULT

    See example overlay    		 Any one of the conditions listed under fault #210 can
    cause an EL motor fault.
    • Check ACU display for more detailed fault info, then call Servo.
    • Open a maintenance report.
    215 POSSIBLE AZIMUTH OSCILLATION

    See example overlay    		 Possible oscillation in AZ axis.
    • Check ACU display for motor currents that are changing polarity.
    • Stow antenna & call Servo group to nvestigate.
    • Open a maintenance report.
    216 POSSIBLE ELEVATION OSCILLATION

    See example overlay    		 Possible oscillation in EL axis.
    • Check ACU display for motor currents that are changing polarity.
    • Stow antenna & call Servo group to nvestigate.
    • Open a maintenance report.


    FRM Related Messages

    ID
    Name
    Cause
    Action
    220 EXCESSIVE SUB-REFLECTOR ERROR

    See example overlay    		 Change in focus > 4 counts**
    Change in focus > 200 counts***
    Change in rotation > 4 counts**
    Change in rotation > 10 counts***
    A two star message indicates that data is not greatly affected.  A three star message indicates that the data is bad.
    • Use the FR overlay to command the subreflector to the correct position.
    • If the correct position cannot be obtained, or if it drifts out of position, open a maintenance report.
    • Contact servo or DCS.
    • The antenna is considered down if the focus or rotation is off by more than 10 counts.
    • Open a maintenance report.
    223 GROUND NOT ZERO VOLTS

    See example overlay    		 Ground is not at zero volts.  The acceptable range is -.045 V to .045 V.
    • Open a maintenance report on M11.
    224 F/R ROT FAULT

    See example overlay    		 FRM will not move in Rotation axis.
    • Use the FR overlay to command the subreflector to the correct position.
    • If the fault remains, open a maintenance report.
    • Contact servo or DCS.
    225 F/R FOCUS FAULT

    See example overlay    		 FRM will not move in Focus axis.
    • Use the FR overlay to command the subreflector to the correct position.
    • If the fault remains, open a maintenance report.
    • Contact servo or DCS.
    226 F/R SYSTEM FAULT

    See example overlay    		 System faults indicate a problem with the FRM system, such as both limits being set at the same time or a cable that is not plugged in.
    • Use the FR overlay to command the subreflector to the correct position.
    • If the fault remains, open a maintenance report.
    • Contact servo or DCS.


    Antenna LO Related Messages

    ID
    Name
    Cause
    Action
    300 L5 GROUND > 0.01V

    See example overlay    		 This message is generated when there is a loose ground connection or a problem in the data set. Do nothing.  The LO/IF group routinely monitors this, and will correct the problem.
    301 L1-J4 5 MHZ REF OUTPUT LOW, <1.5 V

    See example overlay    		 5 MHZ output power on J4 is low.  If this power is too low then there will be many more problems.
    • If there are any LO "out of lock" errors at the same time as this error, contact LO and do not use the antenna.
    • Open a maintenance report.
    302 L1-J3 5 MHZ REF OUTPUT LOW, <1.5 V

    See example overlay    		 5 MHZ output power on J3 is low. If this power is too low then there will be many more problems.
    • If there are any LO "out of lock" errors at the same time as this error, contact LO and do not use the antenna.
    • Open a maintenance report.
    303 L1 10 MHZ OUTPUT LOW, <1.5 VSee example overlay 10 MHZ output power is low. If this power is too low then there will be many more problems.
    • If there are any LO "out of lock" errors at the same time as this error, contact LO and do not use the antenna.
    • Open a maintenance report.
    305 L1 50 MHZ OUTPUT LOW,<1.5 V

    See example overlay    		 50 MHZ output power is low.  If this power is too low then there will be many more problems.
    • If there are any LO "out of lock" errors at the same time as this error, contact LO and do not use the antenna.
    • Open a maintenance report.
    306 L2 VCO TUNING > 5V

    See example overlay    		 The VCO control voltage in the L2 is > 5 volts. This means that the tuning voltage in the oscillator has drifted and needs to be adjusted.
    • If there are any LO "out of lock" errors at the same time as this error, contact LO and do not use the antenna.
    • Open a maintenance report.
    310 L2 COMB OUTPUT LOW, < 2.0 V

    See example overlay    		 The output power of the comb generator in the L2 is low.  If this power is too low then the L6s will not lock and the front end will also have problems.
    • If this error is accompanied by an L6 "out of lock" error (702), notify LO/IF.  The antenna is considered 1/2 down according to the 3 antenna rule.
    • Open a maintenance report.
    311 L3 1200 MHZ VCO TUNING --- SATURATEDSee example overlay The tuning voltage of the 1200 MHZ VCO in the L3 is at +/- 10 volts.  The VCO may be out lock or be very close to it.  It is also possible that the VCO is ok, but that there is a monitor problem. 
    • If no other errors are present (see below), no further action is necessary. 
    • If there are other errors present such as 600 MHZ round trip phase or 1200 MHZ out of lock, do not use the antenna. 
    • Notify LO/IF.
    • Open a maintenance report.
    313 L3 1200 MHZ VCO TUNING NOT -5 V TO +8 VSee example overlay The tuning voltage of the 1200 MHZ VCO in the L3 has drifted out of range.  If the L3 1200 MHZ is still locked, the antenna can still be used. 
    • If the L3 1200 MHZ is out of lock (checker message 511), do not use the antenna.  Notify the LO/IF group.
    • Open a maintenance report.
    314 L3 1800 MHZ VCO TUNING --- SATURATEDSee example overlay The tuning voltage of the 1800 MHZ VCO in the L3 is at +/- 10 volts.  The VCO may be out lock or be very close to it.  It is also possible that the VCO is ok, but that there is a monitor problem. 
    • If no other errors are present (see below), no further action is necessary. 
    • If there are other errors present such as 600 MHZ round trip phase or 1800 MHZ out of lock, do not use the antenna. 
    • Notify LO/IF.
    • Open a maintenance report.
    315 L3 1800 MHZ VCO TUNING NOT -5 V TO +8 VSee example overlay The tuning voltage of the 1800 MHZ VCO in the L3 has drifted out of range.  If the L3 1800 MHZ is still locked, the antenna can still be used. 
    • If the L3 1800 MHZ is out of lock (checker message 520), do not use the antenna.  Notify the LO/IF group.
    • Open a maintenance report.
    316 L4 1200 MHZ RECEIVED LEVEL LOW, < 0.5 VSee example overlay The 1200 MHZ receive level in the L4 at the antenna is low and needs adjusting.  There is a danger of the L8 losing sync at this point.
    • Notify LO/IF. 
    • Watch closely for an L8 "out of lock" error (054).  If this error (054) also occurs, do not use the antenna.
    • Open a maintenance report.
    317  L4 1800 MHZ RECEIVED LEVEL LOW, < 0.5 VSee example overlay  The 1800 receive level in the L4 at the antenna is low and needs adjusting.  There is a danger of losing communications with the antenna or having command parity errors.
    • Notify LO/IF. 
    • If there is difficulty communicating with the antenna, do not use the antenna. 
    • Open a maintenance report.
    321 L3 1200 MHZ VCO OUTPUT LOW, > -0.8 VSee example overlay The 1200 MHZ VCO output power is low.  The L3 will need to be replaced.  The problem is not critical unless other errors occur at the same time.
    • If the L3 1200 MHZ is out of lock (checker message 511), do not use the antenna.  Notify the LO/IF group.
    • Open a maintenence report.
    322 L3 1800 VCO OUTPUT LOW, > -0.8 VSee example overlay The 1800 MHZ VCO output power is low.  The L3 will need to be replaced.  The problem is not critical unless other errors occur at the same time.
    • If the L3 1800 MHZ is out of lock (checker message 520), do not use the antenna.  Notify the LO/IF group.
    • Open a maintenence report.
    323 L1 VCXO TUNING > 2 VSee example overlay The VCXO tuning voltage in the L1 has drifted out of range and needs to be adjusted.  The problem is not critical unless other errors occur at the same time.
    • Open a maintenence report.
    324 L5 5 MHZ PHASE > -0.3 VSee example overlay The 5 MHZ phase monitored in the L5 has drifted to near the boundary and there is a danger of a cycle slip.  The phase needs to be zeroed.
    • Open a maintenance report. 
    325 5 MHZ PHASE JUMP; CYCLE SLIPSee example overlay A 5 MHZ phase jump/cycle slip has occurred.  Some data will be lost.
    • If the problem occurs every few minutes, notify the LO/IF group and do not use the antenna.
    • Open a maintenance report. 
    340 T2 GROUND > 0.15 VSee example overlay This message is generated when there is a loose ground connection or a problem in the data set. Do nothing.  The LO/IF group routinely monitors this, and will correct the problem.
    342 RACK B TEMP NOT 16 TO 23 CSee example overlay The temperature of the B-rack is out of range. 
    • Determine the B rack temperature from the PS display.
    • IF THE TEMPERATURE IS TOO COLD
    • No other action besides the maintenance report is necessary.
    • IF THE TEMPERATURE IS TOO HOT
    • If the temperature is between 24 and 30 degrees C, open a maintenance report. 
    • Watch the temperature to make sure that the condition is static.
    • If the temperature continues to change, then notify HVAC.
    • If the B-Rack temperature is above 30 degrees,   Call HVAC immediately.  The B-Rack must be shut off as soon as possible. At this time, auto shutoff for B-Rack is not available so someone must go to the antenna and shut off the rack or repair the HVAC to prevent damage to the electronics.
    • Open a maintenance report.
    350 ANTENNA T1 PLL INTEGRATOR > 5VSee example overlay The Integrator circuit in the T1 has drifted out of range, and could go out of lock.  The problem is not critical unless there are problems communicating with the antenna. 
    • Open a maintenence report.
    355 ANTENNA T1 MANUAL WARNINGSee example overlay The T1 manual warning flag has been set. 
    • Reset the T1 to clear the flag. 
    • If the flag does not clear, notify the LO/IF group.
    • Open a maintenance report.
    357 ANTENNA T1 NOT LOCKED-PLEASE RESETSee example overlay The T1 has either lost lock or glitched lock. 
    • Reset the T1 from the T1 overlay. 
    • If the T1 will not reset or if it continues to glitch lock notify LO/IF.
    • Open a maintenance report.
    402 RACK B +5 V: ERROR > 0.1 VSee example overlay The +5 volts in the antenna has drifted out of the range 5.0 V to 5.2 V. 
    • If the voltage is not stable or near the limits notify LO/IF.
    403 RACK B -5 V: ERROR > 0.1 VSee example overlay The -5 volts in the antenna has drifted out of the range -5.1 V to -5.3V. 
    • If the voltage is not stable or near the limits notify LO/IF.
    404 L6(A) +15 V: ERROR > 0.2 VSee example overlay The +15 volts in the antenna has drifted out of the  range . 
    • If the voltage is not stable or near the limits notify LO/IF.
    405 L6(A) -15 V: ERROR > 0.2 VSee example overlay The -15 volts in the antenna has drifted out of range. 
    • If the voltage is not stable or near the limits notify LO/IF.
    407 L6(A) -28 V: ERROR > 0.4 VSee example overlay The -28 volts in the antenna has drifted out of range.
    • If the voltage is not stable or near the limits notify LO/IF.
    447 L6(C) +28 V: ERROR < 27.4 V OR > 28.6 VSee example overlay The +28 volts in the antenna has drifted out of range. 
    • If the voltage is not stable or near the limits notify LO/IF.
    506 L2 50 MHZ PLL NOT LOCKEDSee example overlay The 50 MHZ VCO in the L2 has lost lock. 
    • Do not use the antenna.
    • Notify LO/IF.
    • Open a maintenance report. 
    511 L3 1200 MHZ PLL NOT LOCKEDSee example overlay The 1200 MHZ VCO in the L3 has lost lock. 
    • Do not use the antenna.
    • Notify LO/IF.
    • Open a maintenance report. 
    520 L3 1800 MHZ PLL NOT LOCKEDSee example overlay The 1800 MHZ VCO in the L3 has lost lock. 
    • Do not use the antenna.
    • Notify LO/IF.
    • Open a maintenance report. 
    523 L1 VCXO TUNING OUT OF RANGESee example overlay The VCXO tuning voltage in the L1 has drifted out of range and needs to be adjusted.
    • Open a maintenence report.
    526 5 MHZ LOCK SELECTEDSee example overlay The 5 MHZ lock has been selected.  This will occur when there is a problem with the 600 MHZ phase.  Data will be lost. 
    • Reset All LOs from the LO overlay.
    • If 5 MHZ lock is still selected after the reset, do not use the antenna.
    • Notify LO/IF.
    • Open a maintenance report.
    527 ANTENNA LO ABNORMAL STATE SELECTEDSee example overlay This abnormal state occurs when the antenna has been commanded to lock on the 5 MHZ.  The LO system in the antenna needs to be reset.
    • Reset the LO system from the LO overlay.
    • If 5 MHZ lock is still selected after the reset, do not use the antenna.
    • Notify LO/IF. 
    • Open a maintenance report.
    542 RACK B TEMP JUMP >2CSee example overlay There has been a temperature jump in the B-rack of the antenna.
  • Determine the B rack temperature from the PS display.
  • IF THE TEMPERATURE IS TOO COLD
  • No other action besides the maintenance report is necessary.
  • IF THE TEMPERATURE IS TOO HOT
  • If the temperature is between 24 and 30 degrees C, open a maintenance report. 
  • Watch the temperature to make sure that the condition is static.
  • If the temperature continues to change, then notify HVAC.


    • If the B-Rack temperature is above 30 degrees,   Call HVAC immediately.  The B-Rack must be shut off as soon as possible. At this time, auto shutoff for B-Rack is not available so someone must go to the antenna and shut off the rack or repair the HVAC to prevent damage to the electronics.

    • Open a maintenance report.

     
    545 ANTENNA T2 XMT LEVEL OUT OF RANGESee example overlay The T2 transmit level in the antenna is out of range. The T2 probably needs to be replaced and recalibrated. Do nothing.  The LO/IF group routinely monitors this, and will correct the problem.
    546 ANTENNA T2 RCV LEVEL OUT OF RANGESee example overlay The T2 receive level at the antenna is out of range. The antenna needs the levels reset.
    • Open a maintenance report.
    601 CLIPPER LEVEL OUT OF RANGE See example overlay The power level of the IF going in to the sampler module could be too high or too low.  This message could also be caused by sampler threshold voltages that are incorrect.
    • If this message is accompanied by a "Total Power Out Of Range" message (959, 960, 968 or 969), take action described for that checker message.
    • If there is not a "Total Power Out of Range" checker message with this message (959, 960, 968 or 969), swap the sampler module (D1).  Notify the correlator group.
    • Open a maintenance report.
    602 SINE X COSINE TOO LARGE    (sampler related)See example overlay If in continuum mode, the sampler is misadjusted.  If in spectral line mode, ignore.
    • Determine whether the present observing mode is continuum or spectral line. 
    • Open a maintenance report if the present mode is continuum mode.  Ignore the message and take no action if the present mode is spectral line mode.
    • Swap the sampler module (D1).  Notify the correlator group.
    700 L8 OUT OF SYNC. See example overlay L8 is out of synchronization. 
    • Reset the LO system from the LO overlay.
    • Check the LO overlay to determine if the L8 is still out of sync.  If it is out of sync, a message flashes on and off on the LO overlay.
    • Do not use the antenna if the L8 is still out of synchronization after the reset.
    • Notify the LO/IF group.
    • Open a maintenance report.
    701 SYNTHESIZER AT WRONG FREQUENCYSee example overlay When observe file & L6 disagree - probably a lost command; maybe broken L6 or DCS.
    • Check L6 display to determine which L6 is at the wrong frequency (AC or BD).
    • Command the synthesizer (L6) to the correct frequency from the L6 overlay.
    • If the synthesizer cannot be commanded to the correct frequency, the antenna is considered 1/2 down, with regard to the 3 antenna rule.
    • Notify the LO/IF group.
    • Open a maintenance report.
    702 SYNTHESIZER OUT OF LOCKSee example overlay One of the L6s is out of lock. 
    • Check L6 display to determine which L6 is out of lock (AC or BD).
    • Send the L6 to another frequency then back to the required frequency, using the L6 overlay.  Possible frequencies to try are 2690 MHZ and 4010 MHZ.  This may cause the L6 to lock up again.
    • If the L6 does not lock, the antenna is considered 1/2 down, with regard to the 3 antenna rule.
    • Notify the LO/IF group.
    • Open a maintenance report.
    703 LOSS OF AIRFLOW IN VERTEX ROOM    (not currently in use) N/A
    750 IF FILTER(S) MIS-SELECTEDSee example overlay Backend filters in the T4 are not selected properly.
    • Select the filters by going to the BB (baseband) display.
    • If selecting the filter does not fix the problem then swap the T4. 
    • Notify the LO/IF group.
    • Open a maintenance report.


    FE Related Messages

    ID
    Name
    Cause
    Action
    825 A TSYS > 4 TIMES NOMINALSee example overlay The synchronous detector voltage is too low.  Indicates loss of sensitivity, loss of bright sky or bad noise calibration.
    • Open a maintenance report.
    826 A TOT PWR OUT OF RANGE 2.9 TO 3.1See example overlay The receiver gain has changed more than the F4 Automatic Level Control can handle, allowing the Total Power Detector output to vary from its controlled level of 3.0 V.  If the ALC is also less than 0.5 V, the IF is bad.  If the ALC is ok, data from this IF may be bad.
    • If the ALC is < 0.5 V, the data from this IF is bad.  The antenna is 1/4 down, according to the 3 antenna rule.
    • If the ALC is ok, the data still may be bad.  Check the "fringe" display for the presence of fringes.  If there are no fringes, the data from this IF is bad.  The antenna is 1/4 down, according to the 3 antenna rule.
    • Open a maintenance report.
    828 A ALC < 0.5 VSee example overlay The F4 Automatic Level Control is at the limit of its control voltage and is no longer effective.
    • If the A Total Power is also out of range (826), then the data from IF A is bad.   The antenna is 1/4 down, according to the 3 antenna rule.
    • Open a maintenance report.
    830 B TSYS > 4 TIMES NOMINALSee example overlay The synchronous detector voltage is too low. Indicates loss of sensitivity, loss of bright sky or bad noise calibration.
    • Open a maintenance report.
    835 B ALC < 0.5VSee example overlay The F4 Automatic Level Control is at the limit of its control voltage and is no longer effective.
    • If the B Total Power is also out of range (826), then the data from IF B is bad.   The antenna is 1/4 down, according to the 3 antenna rule.
    • Open a maintenance report.
    836 B TOT PWR OUT OF RANGE 2.9 TO 3.1See example overlay The receiver gain has changed more than the F4 Automatic Level Control can handle, allowing the Total Power Detector output to vary from its controlled level of 3.0 V.
    • If the ALC is < 0.5 V, the data from this IF is bad.  The antenna is 1/4 down, according to the 3 antenna rule.
    • If the ALC is ok, the data still may be bad.  Check the "fringe" display for the presence of fringes.  If there are no fringes, the data from this IF is bad.  The antenna is 1/4 down, according to the 3 antenna rule.
    • Open a maintenance report.
    845 C TSYS > 4 TIMES NOMINALSee example overlay The synchronous detector voltage is too low. Indicates loss of sensitivity, loss of bright sky or bad noise calibration.
    • Open a maintenance report.
    846 C TOT PWR OUT OF RANGE 2.9 TO 3.1See example overlay The receiver gain has changed more than the F4 Automatic Level Control can handle, allowing the Total Power Detector output to vary from its controlled level of 3.0 V.
    • If the ALC is < 0.5 V, the data from this IF is bad.  The antenna is 1/4 down, according to the 3 antenna rule.
    • If the ALC is ok, the data still may be bad.  Check the "fringe" display for the presence of fringes.  If there are no fringes, the data from this IF is bad.  The antenna is 1/4 down, according to the 3 antenna rule.
    • Open a maintenance report.
    848 C ALC < 0.5VSee example overlay The F4 Automatic Level Control is at the limit of its control voltage and is no longer effective.
    • If the B Total Power is also out of range (826), then the data from IF B is bad.   The antenna is 1/4 down, according to the 3 antenna rule.
    • Open a maintenance report.
    850 D TSYS > 4 TIMES NOMINALSee example overlay The synchronous detector voltage is too low. Indicates loss of sensitivity, loss of bright sky or bad noise calibration.
    • Open a maintenance report.
    855 D ALC < 0.5VSee example overlay The F4 Automatic Level Control is at the limit of its control voltage and is no longer effective.
    • If the B Total Power is also out of range (826), then the data from IF B is bad.   The antenna is 1/4 down, according to the 3 antenna rule.
    • Open a maintenance report.
    856 D TOT PWR OUT OF RANGE 2.9 TO 3.1See example overlay The receiver gain has changed more than the F4 Automatic Level Control can handle, allowing the Total Power Detector output to vary from its controlled level of 3.0 V.
    • If the ALC is < 0.5 V, the data from this IF is bad.  The antenna is 1/4 down, according to the 3 antenna rule.
    • If the ALC is ok, the data still may be bad.  Check the "fringe" display for the presence of fringes.  If there are no fringes, the data from this IF is bad.  The antenna is 1/4 down, according to the 3 antenna rule.
    • Open a maintenance report.
    867  RACK A -15V: ERROR > 2%See example overlay The -15V supply voltage for the A-Rack is out of tolerance.  This problem does not affect data unless other checker messages indicate a loss of data.
    • Open a maintenance report.
    868 RACK A +5V: ERROR > 2%See example overlay The +5V supply voltage for the A-Rack is out of tolerance.  This problem does not affect data unless other checker messages indicate a loss of data.
    • Open a maintenance report.
    869 RACK A +15V:ERROR > 2%See example overlay The +15V supply voltage for the A-Rack is out of tolerance.  This problem does not affect data unless other checker messages indicate a loss of data.
    • Open a maintenance report.
    878 F5 10 VOLT ERROR > 0.035 VSee example overlay The 10 V precision reference in the F5 module is in error, or the readback of the 10 V precision reference is bad.  If the readback is bad, it may be caused by a bad analog multiplexer in the F5 or a bad A/D converter in the data set.    If the 10 V precision reference is correct, but the readbacks are bad, all of the A/D conversions involving the F5 may be in error.
    • Open a maintenance report.
    879 F5 GROUND: ERROR >0.015 VSee example overlay The ground reference in the F5 module is in error, or the readback of the ground reference is bad.  If the readback is bad, it may be caused by a bad analog multiplexer in the F5 or a bad A/D converter in the data set.    If the ground reference is correct, but the readbacks are bad, all of the A/D conversions involving the F5 may be in error.
    • Open a maintenance report.
    905 F5 TEMPERATURE NOT 20 TO 30 CSee example overlay The temperature monitor in the F5 is out of range, indicating a problem with the cooling/heating air supply to the A-Rack.  A calibration problem with the temperature sensor can also cause this error, even when the temperature is within range.
    • Check the A rack and B rack temperatures on the PS display.
    • If the temperature is too cold, no further action is needed.
    • If the A Rack and B Rack temperatures are above 30 degrees, Call HVAC immediately.  At this time, auto shutoff for A-Rack is not available so you must call HVAC or damage may occur to A-Rack electronics. 
    • If the A rack temperature is greater than 30 degress, but the B rack temperature is ok, Call the Front End Group immediately.  The A-Rack must be shut down before damage occurs to the electronics.
    • Open a maintenance report.
    914 F2 PLL NOT LOCKED AND OBSERVING AT L BANDSee example overlay The F2 is the first LO for L-band (1.5 GHz). The antenna will not fringe at L-band if it is not phase-locked.
    • Do not use the antenna.
    • The F2 should always be locked, even if not observing at L-band.  If the F2 is not locked during observing that is not at L-band, open a maintenance report.  In this case, the antenna can still be used.
    • Open a maintenance report.


    Control Building LO Related Messages

    ID
    Name
    Cause
    Action
    940 L9 1200 MHZ RCV LEVEL < 0.6See example overlay The central 1200 MHZ receive level in the L9 is low.
    • If there the 1200 MHZ PLL is not locked, or there are 600 MHZ round trip phase problems, do not use the antenna.  Contact the LO/IF group.
    • Open a maintenance report.
    941 L9 1800 MHZ RCV LEVEL < 0.6See example overlay The central 1800 MHZ receive level in the L9 is low. If this level goes too low then the antenna data sets will be missing or there will be high monitor parity errors.
    • If there are monitor parity errors, or if the 1800 MHZ PLL is not locked, or if there are 600 MHZ round trip phase problems, do not use the antenna.  Contact the LO/IF group.
    • Open a maintenance report.
    942 L14 1200 MHZ VCO OUTPUT LOW,>-0.6See example overlay The 1200 VCO output power is low. The L14 will need to be replaced.
    • If the 1200 MHZ PLL is not locked, do not use the antenna.  Contact the LO/IF group. 
    • Open a maintenance report.
    943 L14 1800 MHZ VCO OUTPUT LOW, >-0.6See example overlay The 1800 VCO output power is low. The L14 will need to be replaced.
    • If the 1800 MHZ PLL is not locked, do not use the antenna.  Contact the LO/IF group.
    • Open a maintenance report.
    944 L14 1200 MHZ PLL NOT LOCKEDSee example overlay The 1200 MHZ VCO in the L14 has lost lock. The L14 needs to be replaced.
    • Contact the LO/IF group.  Do not use the antenna.
    • Open a maintenance report.
    945 L14 1200 MHZ PLL TUNING NOT -5 TO +8See example overlay The tuning voltage of the 1200 VCO in the L3 has drifted out of range. The VCO should still be locked and ok but will need adjusting.
    • If the 1200 MHZ PLL is not locked, do not use the antenna.  Contact the LO/IF group.
    • Open a maintenance report.
    946  L14 1800 MHZ PLL NOT LOCKEDSee example overlay The 1800 MHZ VCO in the L14 has lost lock. The L14 needs to be replaced.
    • Contact the LO/IF group.  Do not use the antenna.
    • Open a maintenance report.
    947   L14 1800 MHZ PLL TUNING NOT -5 TO +8See example overlay The tuning voltage of the 1800 VCO in the L14 has drifted out of range. The VCO should still be locked and ok but will need adjusting.
    • If the 1200 MHZ PLL is not locked, do not use the antenna.  Contact the LO/IF group.
    • Open a maintenance report.
    948  L11 +15V. ERROR > 0.2See example overlay The +15 volts in the D-rack has drifted out of range. The voltage is not stable or near the limits.
    • If there are no other problems associated with this message, no further action is needed.  The LO/IF group will adjust the power supply.
    • If there communication problems or if the modem (T1) is not locked, open a maintenance report and notify the LO/IF group.
    949  L11 GROUND > 0.015See example overlay This message is generated when there is a loose ground connection or a problem in the data set.
    • If there are no other problems associated with this message, no further action is needed.  The LO/IF group will adjust the power supply.
    • If there communication problems or if the modem (T1) is not locked, open a maintenance report and notify the LO/IF group.
    950 L11 -15V. ERROR > 0.2See example overlay The -15 volts in the D-rack has drifted out of range. The voltage is not stable or near the limits.
    • If there are no other problems associated with this message, no further action is needed.  The LO/IF group will adjust the power supply.
    • If there communication problems or if the modem (T1) is not locked, open a maintenance report and notify the LO/IF group.
    951 CENTRAL T2 GROUND >0.015See example overlay This message is generated when there is a loose ground connection or a problem in the data set. Do nothing.  The LO/IF group routinely monitors this, and will correct the problem.
    952 CENTRAL T2 XMIT LEVEL OUT OF RANGESee example overlay The T2 transmit level in the D-rack is out of range. The T2 probably needs to be replaced and recalibrated.
    • If there are no other problems associated with this message, no further action is needed.
    • If there are command parity errors, notify LO/IF.  Do not use the antenna?
    • Open a maintenance report.
    953 CENTRAL T2 RCV LEVEL OUT OF RANGESee example overlay The T2 receive level in the D-rack is out of range.  The T2 may need to be replaced and recalibrated.  It is also possible that the IF signals are weak or not present.This error can also be caused by interference (RFI).  It is also possible that the front end is not set up properly. 
    • Determine if RFI is present.  Use the spectrum analyzer.  If RFI is found, open a maintenance report about RFI.
    • If no RFI is found, open a maintenance report.  If there are no other problems associated with this message, no further action is needed.
    • If there is no communication with the antenna, contact LO/IF.
    • If this message is accompanied by a "TSYS > 4 TIMES NOMINAL" message (825, 840, 845, or 850), contact the front end group.
    954 CENTRAL T1 IN MANUALSee example overlay The T1 manual warning flag has been set.
    • Reset the T1 module from the T1 overlay, to clear the error. 
    • If the error does not clear make sure that both front panel switches on the T1 module are in the "auto" position.  Reset the T1 module again.
    • If the error still doesn't clear, notify the LO/IF group.
    • Open a maintenance report.
    955 CENTRAL T1 PLL NOT LOCKEDSee example overlay The T1 has either lost lock or glitched lock. Try resetting the T1. If the T1 will not reset or if it continues to glitch lock.
    • Reset the T1 module from the T1 overlay.
    • Check the T1 overlay to see if the T1 module goes back in to lock.  The "lock warn" field should be > 1.4 volts. 
    • If the T1 module will not lock, or if there are commnication problems, contact the LO/IFgroup.
    • Open a maintenance report.
    956 CENTRAL T1 PLL INTEGRATOR >5V.See example overlay The Integrator circuit in the T1 has drifted out of range. The T1 needs to be replaced.
    • Open a maintenance report.
    957 T5-A ALC OUT OF RANGESee example overlay The T5 automatic level control voltage (ALC) is out of range.  It should be in the range of -2.5 V to -6.0 V.  This could be caused by problems with the T5, T4, or sampler.  It could also happen because the IF entering the T5 has a power level that is too low.
    • Check the total power level for the IF that is affected on the BB overlay.  (The level should be in the range of 4.0 V to 8.0 V).
    • If the total power level is within range, notify the LO/IF group.
    • If the total power level is out of range, refer to the action item for checker message 959.
    • Open a maintenance report.
    958 T5-C ALC OUT OF RANGESee example overlay The T5 automatic level control voltage (ALC) is out of range.  It should be in the range of -2.5 V to -6.0 V.  This could be caused by problems with the T5, T4, or sampler.  It could also happen because the IF entering the T5 has a power level that is too low.
    • Check the total power level for the IF that is affected on the BB overlay.  (The level should be in the range of 4.0 V to 8.0 V).
    • If the total power level is within range, notify the LO/IF group.
    • If the total power level is out of range, refer to the action item for checker message 960.
    • Open a maintenance report.
    959  T5-A IF LEVEL OUT OF RANGESee example overlay Total power as monitored in the T5 is out of range.  There could be a problem with the automatic level control circuit in the T5 or sampler.  If the total power is too high, then the T5 is either oscillating or not automatic level controlling.  If the total power is too low, there may not be sufficient power in the IF as it enters the T5, or there could be a problem with the fluke relays.
    • IF TOTAL POWER IS TOO HIGH
    • If the power is too high (>6 volts) (see the BB overlay), reseat the T5.  Check the BB overlay to see if this corrects the problem.
    • If reseating the T5 doesn't fix the problem, swap the T5.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T5 doesn't fix the problem, swap the T4.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T4 doesn't fix the problem, swap the sampler module.  Check the BB overlay to see if this corrects the problem.
    • If the above steps do not fix the problem, the affected IF is bad.  The antenna is considered 1/4 down according to the 3 antenna rule.
    • IF TOTAL POWER IS TOO LOW
    • If the power is too low (<4.0 volts), check the FE overlay to determine if there is sufficient power in the IF.  If there is not sufficient power in the IF, contact the front end group.  The IF is bad, and the antenna is considered 1/4 down according to the 3 antenna rule.
    •  Toggle the Fluke relays by selecting the other Fluke set in this display. You may need to toggle between the Fluke sets several times.  Check the BB overlay to see if this corrects the problem.
    • If toggling the Fluke relays does not fix the problem then swap the T5.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T5 doesn't fix the problem, swap the T4.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T4 doesn't fix the problem, the affected IF is bad.  The antenna is considered 1/4 down according to the 3 antenna rule.
    • If swapping the T4 module doesn't fix the problem, swap the sampler module.  Check the BB overlay to see if this corrects the problem.
    • Notify the LO/IF group.
    • Open a maintenance report.
    960 T5-C IF LEVEL OUT OF RANGESee example overlay Total power as monitored in the T5 is out of range.  There could be a problem with the automatic level control circuit in the T5 or sampler.  If the total power is too high, then the T5 is either oscillating or not automatic level controlling.  If the total power is too low, there may not be sufficient power in the IF as it enters the T5, or there could be a problem with the fluke relays.
    • IF TOTAL POWER IS TOO HIGH
    • If the power is too high (>6 volts) (see the BB overlay), reseat the T5.  Check the BB overlay to see if this corrects the problem.
    • If reseating the T5 doesn't fix the problem, swap the T5.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T5 doesn't fix the problem, swap the T4.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T4 doesn't fix the problem, swap the sampler module.  Check the BB overlay to see if this corrects the problem.
    • If the above steps do not fix the problem, the affected IF is bad.  The antenna is considered 1/4 down according to the 3 antenna rule.
    • IF TOTAL POWER IS TOO LOW
    • If the power is too low (<4.0 volts), check the FE overlay to determine if there is sufficient power in the IF.  If there is not sufficient power in the IF, contact the front end group.  The IF is bad, and the antenna is considered 1/4 down according to the 3 antenna rule.
    •  Toggle the Fluke relays by selecting the other Fluke set in this display. You may need to toggle between the Fluke sets several times.  Check the BB overlay to see if this corrects the problem.
    • If toggling the Fluke relays does not fix the problem then swap the T5.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T5 doesn't fix the problem, swap the T4.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T4 doesn't fix the problem, the affected IF is bad.  The antenna is considered 1/4 down according to the 3 antenna rule.. 
    • Notify the LO/IF group.
    • Open a maintenance report.
    961 T6 +5V. ERROR > 0.1See example overlay The +5 volts in the D-rack is out of range.
    • If there are no other error messages concerning this D-rack, and if there are no communication problems, no other action is needed.
    • If there are other messages concerning LO modules in the D-rack orif there is difficulty communicating with the antenna, open a maintenance report and notify the LO/IF group.
    962 T6 -5V. ERROR >0.1See example overlay The -5 volts in the D-rack is out of range. 
    • If there are no other error messages concerning this D-rack, and if there are no communication problems, no other action is needed.
    • If there are other messages concerning LO modules in the D-rack orif there is difficulty communicating with the antenna, open a maintenance report and notify the LI/IF group.
    963 T6 +28V. ERROR > 0.4See example overlay  The +28 volts in the D-rack is out of range. 
    • If there are no other error messages concerning this D-rack, and if there are no communication problems, no other action is needed.
    • If there are other messages concerning LO modules in the D-rack or if there is difficulty communicating with the antenna, open a maintenance report and notify the LI/IF group.
    964 T6 -28V. ERROR > 0.4See example overlay The -28 volts in the D-rack is out of range. 
    • If there are no other error messages concerning this D-rack, and if there are no communication problems, no other action is needed.
    • If there are other messages concerning LO modules in the D-rack orif there is difficulty communicating with the antenna, open a maintenance report and notify the LI/IF group.

    965    		 L11 VCO OUT OF RANGESee example overlay The VCO in the L11 is out of range. The L11 will need to be replaced for adjustment.
    • If there is not a "600 MHZ RT PHASE JUMP" checker message with this message, no further action is needed.
    • If there is a "600 MHZ RT PHASE JUMP" checker message with this message, notify the LO/IF group.
    • Open a maintenance report.
    966 T5-B ALC OUT OF RANGESee example overlay The T5 automatic level control voltage (ALC) is out of range.  It should be in the range of -2.5 V to -6.0 V.  This could be caused by problems with the T5, T4, or sampler.  It could also happen because the IF entering the T5 has a power level that is too low. 
    • Check the total power level for the IF that is affected on the BB overlay.  (The level should be in the range of 4.0 V to 8.0 V).
    • If the total power level is within range, notify the LO/IF group.
    • If the total power level is out of range, refer to the action item for checker message 968.
    • Open a maintenance report.
    967 T5-D ALC OUT OF RANGESee example overlay The T5 automatic level control voltage (ALC) is out of range.  It should be in the range of -2.5 V to -6.0 V.  This could be caused by problems with the T5, T4, or sampler.  It could also happen because the IF entering the T5 has a power level that is too low. 
    • Check the total power level for the IF that is affected on the BB overlay.  (The level should be in the range of 4.0 V to 8.0 V).
    • If the total power level is within range, notify the LO/IF group.
    • If the total power level is out of range, refer to the action item for checker message 969.
    • Open a maintenance report.
    968 T5-B IF LEVEL OUT OF RANGESee example overlay Total power as monitored in the T5 is out of range.  There could be a problem with the automatic level control circuit in the T5 or sampler.  If the total power is too high, then the T5 is either oscillating or not automatic level controlling.  If the total power is too low, there may not be sufficient power in the IF as it enters the T5, or there could be a problem with the fluke relays.
    • IF TOTAL POWER IS TOO HIGH
    • If the power is too high (>6 volts) (see the BB overlay), reseat the T5.  Check the BB overlay to see if this corrects the problem.
    • If reseating the T5 doesn't fix the problem, swap the T5.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T5 doesn't fix the problem, swap the T4.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T4 doesn't fix the problem, swap the sampler module.  Check the BB overlay to see if this corrects the problem.
    • If the above steps do not fix the problem, the affected IF is bad.  The antenna is considered 1/4 down according to the 3 antenna rule.
    • IF TOTAL POWER IS TOO LOW
    • If the power is too low (<4.0 volts), check the FE overlay to determine if there is sufficient power in the IF.  If there is not sufficient power in the IF, contact the front end group.  The IF is bad, and the antenna is considered 1/4 down according to the 3 antenna rule.
    •  Toggle the Fluke relays by selecting the other Fluke set in this display. You may need to toggle between the Fluke sets several times.  Check the BB overlay to see if this corrects the problem.
    • If toggling the Fluke relays does not fix the problem then swap the T5.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T5 doesn't fix the problem, swap the T4.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T4 doesn't fix the problem, the affected IF is bad.  The antenna is considered 1/4 down according to the 3 antenna rule.. 
    • Notify the LO/IF group.
    • Open a maintenance report.
    969 T5-D IF LEVEL OUT OF RANGESee example overlay Total power as monitored in the T5 is out of range.  There could be a problem with the automatic level control circuit in the T5 or sampler.  If the total power is too high, then the T5 is either oscillating or not automatic level controlling.  If the total power is too low, there may not be sufficient power in the IF as it enters the T5, or there could be a problem with the fluke relays.
    • IF TOTAL POWER IS TOO HIGH
    • If the power is too high (>6 volts) (see the BB overlay), reseat the T5.  Check the BB overlay to see if this corrects the problem.
    • If reseating the T5 doesn't fix the problem, swap the T5.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T5 doesn't fix the problem, swap the T4.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T4 doesn't fix the problem, swap the sampler module.  Check the BB overlay to see if this corrects the problem.
    • If the above steps do not fix the problem, the affected IF is bad.  The antenna is considered 1/4 down according to the 3 antenna rule.
    • IF TOTAL POWER IS TOO LOW
    • If the power is too low (<4.0 volts), check the FE overlay to determine if there is sufficient power in the IF.  If there is not sufficient power in the IF, contact the front end group.  The IF is bad, and the antenna is considered 1/4 down according to the 3 antenna rule.
    •  Toggle the Fluke relays by selecting the other Fluke set in this display. You may need to toggle between the Fluke sets several times.  Check the BB overlay to see if this corrects the problem.
    • If toggling the Fluke relays does not fix the problem then swap the T5.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T5 doesn't fix the problem, swap the T4.  Check the BB overlay to see if this corrects the problem.
    • If swapping the T4 doesn't fix the problem, the affected IF is bad.  The antenna is considered 1/4 down according to the 3 antenna rule.. 
    • Notify the LO/IF group.
    • Open a maintenance report.


    More FE Related Messages

    ID
    Name
    Cause
    Action
    970 K/U/Q LO OUT OF LOCKSee example overlay The F3 is the first LO for K and U and Q bands (23, 15, and 43,  GHz). The antenna will not fringe at these bands if it is not phase-locked
    • Do not use the antenna.
    • The F3 should always be set at a frequency that will lock, even if not observing at K, U, or Q band.  If the F3 is not locked during observing that is not at K, U, or Q bands, open a maintenance report.  In this case, the antenna can still be used.
    • Open a maintenance report.
    971 F12 IN MANUALSee example overlay The F12, the first LO for X-band (8.4 GHz) and the second LO for Q band, has been left switched to "Local" and cannot be controlled remotely. 
    • Do not use the antenna for X or Q band.
    • Requires trip to antenna.
    • Open a maintenance report.
    972 F12 NOT LOCKEDSee example overlay The F12 is the first LO for X-band (8.4 GHz) and the second LO for Q- band . The antenna will not fringe at  these bands if it is not phase-locked.
    • Do not use the antenna if observing at X or Q bands.
    • The F12 should always be set at a frequency that will lock, even if not observing at X or Q band.  If the F12 is not locked during observing that is not at X or Q bands, open a maintenance report.  In this case, the antenna can still be used.
    • Open a maintenance report.
    980 EXCESSIVE A RACK DEWAR TEMPERATURE See example overlay The Dewar for the C, U, and old-style K band (4.8, 15, and 23 GHz) amplifiers is warmer than 30 K. This will increase Tsys.  If the temperature is above 100K, then all data is bad.
    • Check the Cryo overlay to see if the supply and return pressures are approximately equal values.  If the pressures have equalized, CALL CRYO IMMEDIATELY.
    • If the supply and return pressures have not equalized, monitor the dewar temperature for 10-20 minutes.  If the temperature continues to increase after the monitoring period, CALL CRYO IMMEDIATELY.
    • If the temperature is cycling, contact Cryo - but this is not a call out situation.
    • Open a maintenance report.
    981 VLA DEWAR PRESSURE >7 MICRONSSee example overlay There is air in the A rack dewar.  It may be leaking, or it may not have been completely evacuated.
    • If the temperature is too high, the data for C, U, and old-style K band is bad.
    • Open a maintenance report.
    982 CHECK HELIUM PRESSURESee example overlay The supply pressure should be 200 to 300 psi.  The nominal return pressure is 50-75 psi.  The typical failure is when the Supply and Return pressures aproach each other until they are they same.
    • If the return pressure is > 100 psi, or if the supply pressure is < 200 psi, open a maintenance report.
    • Contact the Cryo group.  This is not a call out if the temperature is < 100 K, and if the pressures have not equalized.
    983 8GHZ DEWAR WARMSee example overlay The Dewar for X-band (8.4 GHz) is warmer than its nominal operating temperature. This will increase Tsys.  If the temperature is above 100K, then all data is bad.
    • Check the Cryo overlay to see if the supply and return pressures are about equal values.  If the pressures have equalized, CALL CRYO IMMEDIATELY.
    • If the supply and return pressures have not equalized, monitor the dewar temperature for 10-20 minutes.  If the temperature continues to increase after the monitoring period, CALL CRYO IMMEDIATELY.
    • If the temperature is cycling, contact Cryo - but this is not a call out situation.
    • Open a maintenance report.
    984  L-BAND DEWAR WARMSee example overlay The Dewar for L-band (1.5 GHz) is warmer than its nominal operating temperature. This will increase Tsys.  If the temperature is above 100K, then all data is bad.
    • Check the Cryo overlay to see if the supply and return pressures are about equal values.  If the pressures have equalized, CALL CRYO IMMEDIATELY.
    • If the supply and return pressures have not equalized, monitor the dewar temperature for 10-20 minutes.  If the temperature continues to increase after the monitoring period, CALL CRYO IMMEDIATELY.
    • If the temperature is cycling, contact Cryo - but this is not a call out situation.
    • Open a maintenance report.
    985 Q-BAND DEWAR WARMSee example overlay The Dewar for Q-band (45 GHz) is warmer than its nominal operating temperature. This will increase Tsys.  If the temperature is above 100K, then all data is bad.
    • Check the Cryo overlay to see if the supply and return pressures are about equal values.  If the pressures have equalized, CALL CRYO IMMEDIATELY.
    • If the supply and return pressures have not equalized, monitor the dewar temperature for 10-20 minutes.  If the temperature continues to increase after the monitoring period, CALL CRYO IMMEDIATELY.
    • If the temperature is cycling, contact Cryo - but this is not a call out situation.
    • Open a maintenance report.
    986 K-BAND DEWAR WARMSee example overlay The Dewar for K-band (23 GHz) is warmer than its nominal operating temperature. This will increase Tsys.  If the temperature is above 100K, then all data is bad. 
    • Check the Cryo overlay to see if the supply and return pressures are about equal values.  If the pressures have equalized, CALL CRYO IMMEDIATELY.
    • If the supply and return pressures have not equalized, monitor the dewar temperature for 10-20 minutes.  If the temperature continues to increase after the monitoring period, CALL CRYO IMMEDIATELY.
    • If the temperature is cycling, contact Cryo - but this is not a call out situation.
    • Open a maintenance report.


    More CB LO Related Messages

    ID
    Name
    Cause
    Action
    1000 CHECK REFERENCE PHASE IN 'POINTING' FILESee example overlay The 600 MHZ phase has drifted out of the window previously specified. A new reference phase needs to be set.
    • Follow operations procedures for setting a new window.
    1001 600 MHZ RT PHASE JUMP See example overlay A jump in round trip phase has occurred.
    • Open a maintenance report.
    • Notify the LO/IF group.


    With one exception message numbers 1100 and above are reserved for
    reporting problems deduced from data from antenna "0".

    ID
    Name
    Cause
    Action
    1100 WEATHER STATION MALFUNCTION Caused by one or more of the following conditions:
    1) Wind Speed < 0 V.
    2) Barometer & Temp < 0 V.
    3)  Dewpoint > 4.5 V. (~40 C)
    • Investigate weather station.
    • Use model weather if necessary.
    • Maintenance form.
    • Contact DCS.
    1101 WIND NEAR ANTENNA STOW LIMIT (wind at *CB* > 18m/s)See example overlay High wind detected.
    • Consider stowing array.
    1102 WIND AT ANTENNA NEAR STOW LIMIT (wind at *antenna* >40mph) High wind detected.
    • Consider stowing array.
    1103 CHECK FEED DE-ICER STATE Dewpoint/Temperature indicate possible icing on array.
    • Turn on de-icers for feeds.
    • If the de-icers are not operating, open a maintenance report.  To verify de-icer operation, check Data Set 1, analog mux 104.  The acceptable range is 2.0 V to 3.1 V.
    1104 NO ** SOCORRO POWER Socorro Electric dropped power, generators came up-you know that or you wouldn't be reading screen.  Alarm is also used to stagger slewing to ease inductive load on generators. ?
    1105  DP > TEMPERATURE! TSL failure.
    • Use model weather info.
    • Contact DCS.
    • Open a maintenance report.
    1200 L16 ERRORSee example overlay The L16 has incurred an error. The error could be loss of 5 MHZ or low power.
    • If the L17 associated with the L16 is locked, no further action is necessary.  (If the L17 is out of lock, checker message 1201, 1202, 1203, or 1204 will be generated.)
    • If the L17 is out of lock, follow directions for the checker message that is generated.
    • Open a maintenance report.
    1201 VERIFY FLUKE SETTINGS (A/C)(RACK-1)See example overlay The message occurs when the L17 is out of lock. The L17 will not lock unless the Flukes are set up as follows FLUKE A +2x(FLUKE C) = 350 MHZ.
    • If the Flukes are set up properly then check the frequencies displayed in the Fluke display to make sure they are correct.
    • If the L17 is still out of lock, open a maintenance report.
    • Switch to the back up Fluke set.
    • Notify LO/IF.
    • IF THE L17 STILL WILL NOT LOCK, NOTIFY THE LO/IF GROUP (CALLOUT).
    • FOR EACH L17 THAT IS NOT LOCKED, HALF OF THE IF SIGNALS OF THE ENTIRE ARRAY ARE BAD.
    • Try switching to Fluke set 2.
    • Open a maintenance report.
    1202 VERIFY FLUKE SETTINGS (B/D)(RACK-1)See example overlay The message occurs when the L17 is out of lock. The L17 will not lock unless the Flukes are set up as follows FLUKE D +2x(FLUKE B) = 350 MHZ.
    • If the Flukes are set up properly then check the frequencies displayed in the Fluke display to make sure they are correct. 
    • If the L17 is still out of lock, open a maintenance report.
    • Switch to the back up Fluke set.
    • Notify LO/IF.
    • IF THE L17 STILL WILL NOT LOCK, NOTIFY THE LO/IF GROUP (CALLOUT).
    • FOR EACH L17 THAT IS NOT LOCKED, HALF OF THE IF SIGNALS OF THE ENTIRE ARRAY ARE BAD.
    • Try switching to Fluke set 2.
    • Open a maintenance report.
    1203 VERIFY FLUKE SETTINGS (B/D)(RACK-2)See example overlay The message occurs when the L17 is out of lock. The L17 will not lock unless the Flukes are set up as follows FLUKE D +2x(FLUKE B) = 350 MHZ.
    • If the Flukes are set up properly then check the frequencies displayed in the Fluke display to make sure they are correct. 
    • If the L17 is still out of lock, open a maintenance report.
    • Switch to the back up Fluke set.
    • Notify LO/IF.
    • IF THE L17 STILL WILL NOT LOCK, NOTIFY THE LO/IF GROUP (CALLOUT).
    • FOR EACH L17 THAT IS NOT LOCKED, HALF OF THE IF SIGNALS OF THE ENTIRE ARRAY ARE BAD.
    • Try switching to Fluke set 2.
    • Open a maintenance report.
    1204 VERIFY FLUKE SETTINGS (A/C)(RACK-2)See example overlay The message occurs when the L17 is out of lock. The L17 will not lock unless the Flukes are set up as follows FLUKE A +2x(FLUKE C) = 350 MHZ.
    • If the Flukes are set up properly then check the frequencies displayed in the Fluke display to make sure they are correct. 
    • If the L17 is still out of lock, open a maintenance report.
    • Switch to the back up Fluke set.
    • Notify LO/IF.
    • IF THE L17 STILL WILL NOT LOCK, NOTIFY THE LO/IF GROUP (CALLOUT).
    • FOR EACH L17 THAT IS NOT LOCKED, HALF OF THE IF SIGNALS OF THE ENTIRE ARRAY ARE BAD.
    • Try switching to Fluke set 2.
    • Open a maintenance report.
    1205 L12 OUT OF LOCK

    See example overlay    		 This indicates when the 19.2 Hz is out of lock.
    • Notify LO/IF. 
    • Switch Master Racks.
    • Open a maintenance report.
    1206 WEST ARM WG PRESSURE PROBLEM

    See example overlay    		 The nominal pressure of nitrogen in the waveguide is 4 lbs.  A drop in pressure indicates a leak 
    • Check the waveguide overlay.  If the waveguide pressure drops below 2.5 lbs, CALL CRYO IMMEDIATELY.
    • Open a maintenance report.
    1207 NORTH ARM WG PRESSURE PROBLEM

    See example overlay    		 The nominal pressure of nitrogen in the waveguide is 4 lbs.  A drop in pressure indicates a leak
    • Check the waveguide overlay.  If the waveguide pressure drops below 2.5 lbs, CALL CRYO IMMEDIATELY.
    • Open a maintenance report.
    1208 EAST ARM WG PRESSURE PROBLEM

    See example overlay    		 The nominal pressure of nitrogen in the waveguide is 4 lbs.  A drop in pressure indicates a leak
    • Check the waveguide overlay.  If the waveguide pressure drops below 2.5 lbs, CALL CRYO IMMEDIATELY.
    • Open a maintenance report.