GBT OPERATIONS PROCEDURES

Number: OP-02

Title: Antenna Control Via The NRAO M&C System

Last Revision: 01 MAY 02

Warnings

Info

Portions of this procedure assume the Operator Control Unit (OCU) currently has control and that you must initially login to a Unix/Linux workstation. Some steps may be omitted depending on the current state of these systems and the antenna.

General

The GBT servo system has four major modes of computerized control: The OCU, Operator Control Terminal (OCT), Portable Control Terminal, and the NRAO M&C System. The following information describes procedures for allowing control of the GBT via the NRAO M&C System. 

Passing Antenna Control to the NRAO M&C System

STEP

ACTION

1

From an appropriate Unix/Linux workstation, login to the GBT Operations account. From the login window enter: gbtops followed by the password when prompted (see operations list of current passwords if needed)

2

Open the CleoLauncher using the same Xterm window above. Enter: cleo (The CleoLauncher will appear)

3

From the CleoLauncher launch Messages on monitor of choice (the Cleo Message window will appear)  

4

 From the CleoLauncher launch Antenna on the monitor of choice (the Antenna and Optics Monitor windows will appear)

From the Antenna Monitor window:

  • Click on the Control button (the Antenna Control window will appear)

  • Arrange the Antenna windows as desired   

  • Go to the Drives tab of the Antenna Control window and verify all drives are DISABLED

  • From the Drives panel, set the CCU and SCU control modes to ENABLED (clears the SCU and CCU to NRAO link down messages)

5

From the OCU/OCT, enable control for the NRAO M&C System:

  • From the menu selection window, select the Control menu (ctrl F5)

  • Go to the CCU control option menu and select NRAO Allowed Control

  • Go to the SCU control option menu and select NRAO Allowed Control

6

From the Antenna Control window click on the Get Control button (the button will change to Halt within 20 seconds. If not, check for error messages)

7

From the Drive tab on the Antenna Control window, verify NRAO as the control source for the CCU and SCU

8

Verify that no CCU and SCU "database empty" messages are present on the OCU/OCT or Cleo Message windows

9

From the Antenna Control tab of the Antenna Control window, set the operation mode to DoScan

10

The NRAO M&C System now has control of the GBT. Ensure the elevation stow pin is retracted before attempting any elevation movements

Preparing for an Observing Run

STEP

ACTION

1

Enable antenna control via the NRAO M&C System (complete the procedure "Passing Antenna Control to the NRAO M&C System")

2

Retract the elevation stow pin. 

3

 Go to the Antenna Control tab of the Antenna Control window and:

Set the coordinate mode to Azimuth/Elevation

Press the Update button (sets the current antenna position as the commanded position)  

4

 Determine which optics (Prime Focus of Gregorian) and receiver will be used.

If an optics configuration change is required, proceed to the procedure "Changing GBT Optics" before continuing to step 5

If a receiver change is required, proceed to the procedure "Changing Gregorian Receivers" before continuing to step 5

5

Check Antenna Monitor window to confirm the desired optics and receiver are in place

6

Go to the Drives tab of the Antenna Control window and ENABLE the drives required (Az/El, Prime Focus, and/or Sub Reflector) 

7

 Go to the Antenna Control tab of the Antenna Control window and:

Set the operation mode to DoScan

Set the coordinate mode to the observing coordinate system desired 

8

 From the CleoLauncher launch Scan Coordinator (the Scan Coordinator window will appear)

Press the Unlock button followed by the System Selection button (a system selection menu will pop up)

Select Antenna and any of the other items required. Close the menu when done  

9

The GBT Observe program can now be used to control the telescope

Changing GBT Optics

STEP

ACTION

1

Go to the Drives tab of the Antenna Control window and DISABLE the Az/El drives

2

 Go to the Antenna Control tab of the Antenna Control window and:

Set the operation mode to Change Optics

Set the optics mode as desired from the following options: 

  • PrimeFocusOptics (deploys Prime Focus boom)

  • GregorianOptics (retracts Prime Focus boom if extended)

  • StowOptics (retracts Prime Focus boom and stows the sub reflector)

3

Go to the Antenna Control window and press the Move To button (initiates the optics mode change. The antenna will be in an error state during the change)

4

Monitor the message window for any problems related to the optics change 

5

Verify completion of the optics change (check the optics status information on the Antenna Monitor window)

6

Return to step 4 of the "Preparing for an Observing Run" procedure or resume prior observing operation

Changing Gregorian Receivers

STEP

ACTION

1

Confirm the telescope is in Access position (Elevation = 77.840 degrees). Use the NRAO M&C System to move the telescope to access position if needed

2

Go to the Drives tab of the Antenna Control window and DISABLE the Az/El drives

3

Verify the receiver turret is horizontal (check the Cleo message window or the OCU/OCT status window for a Turret Horizontal message)

4

 Go to the Antenna Control tab of the Antenna Control window and:

Set the operation mode to SelectFeed 

Select the desired receiver under the Gregorian Receiver menu. They include:

  • Gregorian Rx 1 (L band; 1_2 (1.15-1.73GHz); turret position/angle=N1/359°)

  • Gregorian Rx 2 (C band; 4_6 (3.95-5.85GHz) turret position/angle=N2/299°)

  • Gregorian Rx 3 (vacant; turret position/angle=N3/259°)

  • Gregorian Rx 4 (Ku band; 12_18 (12-15.4GHz) turret position/angle=N4/219°)

  • Gregorian Rx 5 (S band; 2_3 (1.73-2.6GHz) turret position/angle=N5/179°)

  • Gregorian Rx 6 (K band; 18_26 (18-26.5GHz) turret position/angle=N6/139°)

  • Gregorian Rx 7 (Holography; turret position/angle=N7/99°)

  • Gregorian Rx 8 (X band; 8_10 (8-10.1GHz) turret position/angle=N8/59°)

5

Go to the Antenna Control window and press the Move To button (initiates turret rotation/receiver change) 

6

Monitor the message window for any problems related to the receiver change 

7

Verify completion of the receiver change (check Gregorian Receiver status information on the Antenna Monitor window )

8

Verify Turret Locked is displayed in the Turret Lock status block of the Antenna Monitor window

9

Return to step 4 of the "Preparing for an Observing Run" procedure or resume prior observing operations

Prepared by: Dave Rose

Modified by: Eric Knapp

Last modified: 01 MAY 02