TELESCOPE OPERATIONS

• M&C not passed control by the OCU (Pass control by OCU or OCT).
• Illegal commanded position in GO/Cleo (Check positon).
• Illegal commanded center frequency imbedded in the glish setup script (Check script for erroneous value).

• Az/El drives not enabled (Check Drives Tab; enable drives).
• M&C does not have control (Check Drives Tab; CCU should be set to Enabled with NRAO as control source).
• GBT control may be in simulated mode (Check to see if sourced to Real mode).
• Oper. Mode not set to Do Scan (Set to Do Scan).
• Illegal commanded position in GO/Cleo (Check commanded positions. Pressing the Update button then reentering coordinates or reselecting coordinate system may also help.).
• Problem with observers setup script (Illegal position, coordinate mode, observing frequency, or combination. Check script for problems).
• Az/El movement inhibited due to E-Stop or Soft Stop button depressed (Check/clear E-stop axis faults).
• Antenna in SafeMode or SafeHoldMode state (Check message window for systems not enabling properly; clear faults).
• Antenna/Antenna Manager in fatal fault status (Check message window; clear faults).
• Loss of Manager, Accessor, or Transporter (Check message window for host computer failure; restart host system if required).
• No power to feed arm servo systems (Check circuit breakers in D1-A (Level 1, Power Substation) and/or D-15 (Level 3, Receiver Room)).

• M&C does not have control (Check Drives Tab; CCU should be set to Enabled with NRAO as control source).
• Oper. Mode not set to UnstowAzEl (Set to UnstowAzEl).
• Movement inhibited due to E-Stop or Soft Stop button depressed (Check/clear E-stop axis faults).
• M&C Software failure (Verify by trying to complete move using the OCU/OCT. Report M&C problem to computing division if required).
• Mechanical failure (Report problem to maintenance).

• M&C does not have control (Check Drives Tab; CCU should be set to Enabled with NRAO as control source).
• Oper. Mode not set to StowAzEl (Set to StowAzEl).
• Stow pin insertion inhibited. Stow pin not aligned with stow hole (Check elevation encoder position).
• Movement inhibited due to E-Stop or Soft Stop button depressed (Check/clear E-stop axis faults).
• M&C Software failure (Verify by trying to complete move using the OCU/OCT. Report M&C problem to computing division if required).
• Mechanical failure (Report problem to maintenance).

• Unstow command from M&C or OCU still running in background (Do allstop from OCU/OCT after pulling stow pin).

• Turret rotation inhibited. Antenna not in Access position (Verify elevation is 77.850).
• M&C does not have control (Check Drives Tab; SCU should be set to Enabled with NRAO as control source).
• Oper. Mode not set to SelectFeed (Set to SelectFeed).
• Movement inhibited due to E-Stop or Soft Stop button depressed (Check/clear E-stop axis fault).
• Turret rotated into a limit (Check turret location in Optics Monitor window or on OCU/OCT. If in limit and cannot move, notify maintenance).
• M&C Software failure (Verify by trying to complete move using the OCU/OCT. Report M&C problem to computing division if required).
• Mechanical failure (Report problem to maintenance).

• Computer or turret alignment switch not sensing correct turret positioning (Command to a position at one end of the turret wrap. Follow this by commanding to the other end. Retry to desired position. If not successful after repeated tries, notify maintenance).

• Confirm turret stow pin is extended, turret locked.

• Subreflector not enabled (Check Drives Tab; enable control to Subreflector servos).

• SCU not in M&C control (Check Drives Tab; SCU should be set to Enabled with NRAO as control source).

• Subreflector Mode on Antenna Control window not set correctly (Set to to one of the subreflector modes).

• SCU not enabling properly (Try passing control to the OCU/OCT then back to M&C again. If no response, reboot SCU Interface).

• A servo axis is in a limit (Check Subr Position Ctrl Tab; command axis out of limit).

• No power to feed arm servo systems (Check circuit breakers in D1-A (Level 1, Power Substation) and/or D-15 (Level 3, Receiver Room)).

• M&C Software failure (Verify by trying to complete move using the OCU/OCT. Report M&C problem to computing division if required).

• Mechanical failure (Report problem to maintenance).

• One or more axis exceeded delta limits (If only "limit" or "warning" messages are noted, use OCU, OCT, or M&C to slowly back out the problem axis. If final limit messages are noted, the PMU must be used at the subreflector to slowly back out the problem servos).

• Prime Focus not enabled (Check Drives Tab; enable control to Prime Focus servos).

• SCU not in M&C control (Check Drives Tab; SCU should be set to Enabled with NRAO as control source).

• Subreflector Mode on Antenna Control window not set correctly (Set to Prime mode).

• SCU not enabling properly (Try passing control to the OCU/OCT then back to M&C again. If no response, reboot SCU Interface).

• A servo axis is in a limit (Check Prime Focus Ctrl Tab; command axis out of limit).

• No power to feed arm systems (Check circuit breakers in D1-A (Level 2, Power Substation) and/or D-15 (Level 3, Receiver Room)).

• M&C Software failure (Verify by trying to complete move using the OCU/OCT. Report M&C problem to computing division if required).

• Mechanical failure (Report problem to maintenance).

• Subreflector not fully stowed.

• No power to feed arm systems (Check circuit breakers in D1-A (Level 1, Power Substation) and/or D-15 (Level 3, Receiver Room)).

• Mechanical failure (Report problem to maintenance).

• Subreflector not fully stowed (Stow it).

• No power to feed arm systems (Check circuit breakers in D1-A (Level 1, Power Substation) and/or D-15 (Level 3, Receiver Room)).

• Mechanical failure (Report problem to maintenance).

• M&C does not have control (Check Drives Tab; CCU and SCU should be set to Enabled with NRAO as control source).

• Oper. Mode not set to ChangeOptics (Set to ChangeOptics).

• Subreflector not fully stowed (Stow it).

• No power to feed arm systems (Check circuit breakers in D1-A (Level 1, Power Substation) and/or D-15 (Level 3, Receiver Room)).

• M&C Software failure (Verify by trying to complete move using the OCU/OCT.).

• Mechanical failure (Report problem to maintenance).

Receivers and IF

• Incorrect attenuation at LO1 (Adjust Pwr (dbm) value if set manually).

• Incorrect sky frequency for receiver selected (Select correct frequency_).

• LO has reset itself back to default values (sky frequency=1234). (Reset with correct parameters. Also check all other parameters).

• Receiver not selected or routed properly on LO1 (Check for proper selection/routing).

• Power insufficient due to filter selection (Check or change filter at receiver).

• Receiver manager in OFF state (Turn ON).

• Wrong device controlling calibration (Check switch signal selector settings).

• Cryogenics set to off (Call maintenance. Set to cooling).

• Cryogenics compressor failing (Check compressor supply/return readings for nominal values).

• Helium pressure low (Lines may require recharging; call maintenance).

• Loss of YGOR Manager, Accessor, and/or Transporter (Reset via reset box (gbtaio1, gbtaio2) or TaskMaster command).

• Notch Filter is not turned on or malfunctioning (Cycle OFF then ON and recheck data).

• Wrong filter selected (Check/select filter compatible with receiver).

• Laser power to optical receiver channel is off (Turn on).

Backends

DCR

• Loss of YGOR Manager, Accessor, and/or Transporter (Reset via reset box (gbtdcr) or TaskMaster command).

• Signals not routed correctly (Check via Device Explorer application).

• Not set as the switching signals master (Launch Switch Signals Selector and check/set DCR as switching source).

• Internal software communication failure (Try to correct by changing phase table settings via Scan Coordinator followed by a "prepare").

• Accessor has lost contact with the device's singleboard computer (Reset via reset box, TaskMaster commands, or other current guidance).

• DCRServer on vortex hung in state shown (Possible fixes: Aborting observation via the Scan Coordinator. Reboot the DCR via the reset box. Stop/restart process via TaskMaster commands).

-- DavidRose - 27 Mar 2007