PRECAUTIONS:

A) The control room audio system should be set to monitor noise in the dome generated by the tracker.

General Description:

The following procedure will initialize the TCS and Tracker for night use.

Initial Conditions

A) The tracker control system computer monitor and keyboard in the control room will be used. Currently this is the right most monitor and keyboard at the TO’s workstation. The TCS should be powered up and at a login prompt.

B) The tracker is not initialized and is powered down i.e. the red lamp on the Tracker 3P Box (T3P box) is not lit. The T3P box is the rectangular metal box located to the right of the mouse pad.

C) The tracker’s position should be at center. This can be verified visually by checking the tracker’s position from the dome. If the tracker is positioned near any of its limits follow items 5.10 – 5.13 below.

1.1 Log on as ‘controls’ at the prompt on the TCS monitor.

1.2 Wait for the command prompt ‘tcs controls (1)’ to appear.

2.1 At the command prompt type ‘sx’ and press enter.

2.2 Wait for the GUI to initialize and three shells to come up on the screen. This will take about 2 minutes. The three shells are, in order from left to right and top to bottom, PMAC State Monitor, TS (crockett) and TCS main.

3.1 In the TS (crockett) shell type the command ‘tss’ in small case and press the enter key.

3.2 Pay attention to the text in this shell after the tss command is entered. There will be a point when you will be prompted to power the tracker up.

3.3 Once the prompt is reached power the tracker up by pushing the black tracker 3P button on the electronics rack to the right and hold the button down for about 1 second. The red light to the right of the black button will come on indicating power is supplied to the tracker. Press the enter key. If the red light does not stay lit see Fault Conditions and Solutions A) or B), depending which one applies.

3.4 All the positional data for the tracker will be displayed in the crockett shell. Notice what the position numbers are for the upper and lower x, and y. If the tracker is centered the numbers for upper and lower x should be around –2 and y should be around 73.

4.1 Go to the structure computer by doing a ‘control twiddle’ to get a menu. Select STRUCTURE then press the ‘escape’ key. The monitor display will change from the TCS computer to the structure computer.

4.2 Push the ‘space bar’ to activate the screen.

4.3 Push the ‘control’ and ‘F5’ keys to activate the control window.

4.4 Use the ‘space bar’ to toggle from OCU TAKE CONTROL to COMPUTER ALLOWED CONTROL and press ‘enter’. ‘Computer allowed control’ must be selected in order for the structure to be properly controlled from the TCS interface.

4.5 Go back to the TCS computer display on the monitor.

4.6 In the TCS main shell type ‘Tcs’ at the prompt and press enter. This command is case sensitive.

4.7 After a moment a graphical user interface will come up followed by a small SYSTEM INITIALIZATION window. The window will show that INITIALIZE TRACKER: NORMAL has been selected automatically.

4.8 In this same window click on the box next to ENABLE STRUCTURE and click on the OK button at the bottom of the window.

4.9 Wait a few seconds and watch the command lines as they come up in the TCS main shell. If the structure has been enabled the letters ‘ACK’ will appear on a line in the TCS main shell.

4.10 To test the structure, go to the graphical user interface and click on the NEXT menu at the top left of the interface and choose CCAS. The structure should lift, rotate to the CCAS position, and set down. The structure is now ready to begin night operations.

5.1 An initialize search should be completed on the tracker to ensure full confidence that the tracker knows its position before beginning night operations. Go to the interface and click on the TOOLS menu. Choose ‘TRACKER POSITION’. A small window will appear showing the trackers current position. Click on the OK button at the bottom.

5.2 A new window will appear asking you too either select TRACK, SLEW, or CANCEL. Select TRACK. The tracker motors for tracking will now be enabled. This can be verified by checking the PMAC State Monitor shell. The track motors will have ‘enabled’ next to them.

5.3 Now go back to the TOOLS menu and select ‘INITIALIZE TRACKER…’.

5.4 A small window will appear. Select INITIALIZE SEARCH. The tracker will now go through and find accurate positions for the hexapods, y, rho, and upper and lower x.

5.5 The ‘initialize search’ process will take about ten minutes to complete. During the process use the video monitor and the various positions of the audio system microphones to discern correct movement, and sounds that may indicate a mechanical problem.

5.6 Once the process is complete the upper and lower x should be at a position of around 24 with both upper and lower x position numbers matching, and y should be located at 157.

5.7 There should be green lights next to each item on the small ‘tracker initialization’ window. Close this window out. and click the red ‘abort’ button on the interface. This command stops the motors and sets the brakes. Once again use the PMAC State Monitor shell to confirm that the brakes are set.

5.8 Do not click on the ‘red abort’ button until the upper and lower x are reading the same position number. Even if a ‘green board’ has been received indicating that the initialize search process is completed, the upper and lower x are still going through the process and the numbers have not settled down to indicate the same position for both the upper and lower x.

5.9 Once the upper and lower x position numbers are the same click on the ‘red abort’ button on the TCS interface. This command stops the motors and sets the brakes. Once again use the PMAC State Monitor shell to confirm that the brakes are set. The tracker is now ready to commence night operations.

5.10 If the tracker has been left up near the limits from previous operations, the tracker will have to be moved a small distance before an initialize search can be completed. Otherwise during the initialization process the tracker would be driven up into the limits and the search would not be completed.

5.11 As an example lets say the tracker is at the upper right position which yields an upper and lower x position of around 1598 and a y position of around 1629.

5.12 After step 4.10 above go to the TOOLS menu and select tracker position. Enter x and y positions of 1400. Then chose either TRACK or SLEW to move the tracker to the position selected.

5.13 Now an initialize search can be completed without driving the tracker up into the limits.

Fault Conditions and Solutions

A) The red light on the T3P box does not stay lit after pressing ‘enter’ and the tracker does not power up. Also, the PMAC State Monitor shell will display ‘page is not updating’ message.

1) Exit crockett then repeat steps outlined in section 3.0 until tracker powers up.

B) ‘SKEW LIMIT SWITCH TRIGGERED!!! STOP!!!’ message is displayed in the PMAC State Monitor shell and the tracker will not power up.

1) Check to see if an emergency stop button has been pushed by looking at the display on the rack to the right. If an emergency stop button has been pushed a red light will be lit next to the location.

2) Discern why the button was pushed and make sure the situation is resolved. Make sure the button that was pushed is in the out position and then repeat steps in section 3.0 above.

3) If an emergency stop button was not pushed check the upper and lower x values to make sure they are not different by more than 15 mm. If they are wait for the TO to arrive before continuing.

4) If an emergency stop button has not been pushed and item 3 above is not the case then check the glycol control box for an EF5 fault. An EF5 is an external power fault. If an EF5 fault has occurred push the reset button on the box and then restart the unit. Check the glycol flow gauge on the equipment rack in the control room for flow rate.

5) If 1-4 above have not occurred then exit and restart crockett until tracker stays powered up.

a) Put the cursor within the crockett shell and press the ‘backspace’ key. Type ‘exit’ and press ‘enter’. Repeat steps as outlined in section 3.0 above to power tracker up.

6) If the TCS interface is up when the skew limit switch error occurs, then do the following.

a) Go to the TOOLS menu and select TRACKER SHUTDOWN.

b) Then go back to the TOOLS menu and select RELINQUISH CONTROL OF THE TRACKER.

c) Once again under the TOOLS menu disenable the structure.

d) Select the file menu and exit the TCS interface.

e) Place the cursor in the crockett shell, do a ‘backspace’ followed by typing ‘exit’ at the crockett prompt and press ‘enter. This exits the crockett software.

f) Now repeat steps as outline in 3.0 above to bring crockett back up.

C) Core Dump Error.

1) If a core dump fault has occurred the tracker will not power up and the error message ‘GATFloating exception (core dumped)’ will be displayed on crockett.

2) To clear the error, exit to the main prompt by doing a backspace and then typing exit in crockett.

3) At the prompt type ‘pe xy’ and press ‘enter’.

4) At the pe xy prompt that appears type ‘$$$’ and press ‘enter’.

5) Do a ‘Ctrl D’ to exit the utility.

6) Power up the tracker as outlined in section 3 above.

D) Either an XY or a Rho fault is displayed on the TCS GUI.

1) Reset the appropriate amp on the T3P box by toggling the switch.

2) Click on the red ‘ABORT MOVE’ button on the TCS GUI.

3) The fault should clear. If not, repeat 1 and 2.

4) If the rho fault occurs again the PFIP should be checked to make sure there is nothing hindering movement of the rho stage.

Method for System Shutdown

A) The method is as outline in B).6), items a) thru e) above, with the following additions.

1) After TRACKER SHUTDOWN is selected from the TOOLS menu an alarm will sound from the equipment rack. Wait until this alarm has quit sounding before going to the next step and selecting RELINQUISH CONTROL OF THE TRACKER.

2) Once the crockett software has been exited, put the cursor in the TCS background and left click. A menu will appear; select exit from it. Then left click ‘OK’. This action will exit the TCS software, and concludes the system shutdown method.

Special Tracker Procedures

A) Instructions for Manually Controlling the Tracker Rho Brake.

1) Discussion: The rho brake system is a magnetically held mechanism. Magnets and springs hold the brake open or closed to avoid heat dissipation on a solenoid system. Therefore there are two PMAC variables that control the rho brake: M40, which controls the state of the brake, and M41 which controls the ‘pull’ mechanism that will pull the brake to release it. The pull mechanism is a solenoid type device. The sequence to release the brake is to release the brake mechanism (M40=1), then activate the pull mechanism for 1 second (M41=1), then deactivate the pull mechanism (M40=0), and finally set the brake mechanism (M40=0). The activation time for the pull mechanism is not rigid to avoid heat dissipation.
In addition to controlling the brake the safety plc, plc30, must also be shutdown. Plc30 monitors the state of the motors and the brakes. Anytime it sees a motor off, the plc commands the associated brake to set. Plc30 is primarily to prevent back drive on the Y axis. Make sure that plc30 is enabled when the procedure for controlling the rho brake is finished.

2) Points to watch out for:

a) The first character that is typed at tss will cause the cursor to move to the command line. The second character will start the command buffer. Make sure the command gets entered correctly.

b) Be aware of the position and status of the rho stage. Don’t release the brake if the stage is out of balance and there is a chance that the stage could swing down.

c) Verify that the command is correct before sending it. It is very easy to type the wrong M variable number and change something you don’t want to change.

3) Procedure for controlling the rho brake.

a) On the crockett shell start tss, if the program is not already running, by typing ‘tss’ at the prompt. Do not start TCS.

b) At the crockett prompt type “xy displc30” and press ‘enter’.

c) Now release the brake. At the prompt enter the command “xy m40=1m41=1”, then enter the command “xy m41=0.

d) To set the brake enter the command at the crockett prompt “xy m40=0”.

e) To shutdown enable plc30 by entering the command “xy enaplc30”.

f) This concludes the rho brake procedure.