BCPM Observing Checklist

A short (no, really!) description of how to observe with the BCPM at the GBT.

Logging In
Pulsar Scripts
Cleo Windows
Miscellaneous including Sample Time Table
Writing Backup tapes

:: reference to more pulsar observing support information.

(Note: at present, only the BCPM2 computer is working: therefore, log in only to bcpm2, and set the BCPM manager to control bcpm2)

Logging In

Log into naiad as gbtops (get password from Operator).
Make sure the Operator has given gbtops@naiad permission to use the devices and move the antenna.
Left screen:

Pulsar RF/IF Setup

If you are also running the spigot, you should skip this step!!

On the right screen on NAIAD, start a couple of xterms.
In one xterm, start up the Pulsar Setup GUI called PSRGUI. (This glish function is at /opt/local/bin/PSRGUI).

To configure the GBT RF/LO/IF start by selecting the reciever, in the upper left corner of the GUI. Next configure the receiver by selecting CONFIG RCVR button, which will take a few seconds to execute.

If you have trouble with the PSRGUI the original setup glish scripts are documented in the previous version of this guide.

Cleo Windows

On a different desktop on the naiad screen, start the Cleo Launcher.
You will need to launch the following screens: Unlock each of the screens.
In Device Explorer, double-click on the BCPM device. Then go to the "Managers" menu and select "On". This should start the "init" sequence on the BCPM: lots of info should scroll by in the blue command-line window. If this does not happen, see
Check to see that the hybrid/gain settings, LO1 and Converter Rack LO settings are as expected for your observing setup.
If using the PF1 receiver, adjust the attenuators so that the IF powers are about 1.0.


I usually start GO from another xterm on the same desktop where I ran the pulsar setup script.
Type "GO T" and deselect the spectometer before starting the main GUI.
You will probably need the "Observing Table" and "BCPM" panels, both of which can be started from the "Backends, etc." button.
Reminder: Never swipe text that you want to delete from the GO windows! Type in the full path to your observing table in the "Observing Table" window and hit "Load". The message window at the bottom should say that the table is OK; if not, edit the file for mistakes.
In the BCPM panel, make sure the correct sub-manager is selected (currently only bcpm2 works) and select the desired bandwidth, polarization summing and sample rate. A table converting the mysterious "X2", etc. sample times to microseconds can be found
Select observing mode: you must run a scan in Monitor mode with the correct BW, pol summation and sample time before taking any data!
If in Search mode, select: Timing and Stokes modes do not work yet. Sorry!


Choose the right IF input! In the blue command-line window, type "setif 1" for 600/800/Lband, "setif 2" for 340/450/S-band and "setif 3" for 85-3.

The BCPM is connected to Converter Modules 4 and 8 (IF 1), Converter Modules 12 and 16 (IF 2) and 85-3 610 MHz (IF 3).

The PSRGUI program will set up the entire GBT IF chain for the BCPM. The PSRGUI uses the following equations for setting up the Converter rack LO2 frequency. The BCPM input IF center frequency (FBCPM_Center) is 400 MHz, so the Converter Module LO2 frequency (FLO2) is set by the following equation:

FLO2 = 10500 + FOptical_Receiever_Center - FBCPM_Center MHz

Different Receivers have different Optical Receiver output center frequencies (FOptical_Receiver_Center). For the S band system, the LO1 Sky frequency corresponds to 6000 MHz IF frequency:

FLO2_S = 10500 + 6000 - 400 = 16100 MHz

For L band, the LO1 Sky frequency corresponds to 3000 MHz IF frequency:

FLO2_L = 10500 + 3000 - 400 = 13100 MHz

For Prime Focus 1, the LO1 Sky frequency corresponds to 1080 MHz IF frequency:

FLO2_PF1 = 10500 + 1080 - 400 = 11180 MHz

A typical sequence is: Monitor scan, cal scan, data scan. Here are procedures for each.

Monitor Scan:

Cal Scan:

Data Scan:

After observing:

Turn off the BCPM Manager in DevExplorer, then quit the BCPM gui.



Writing backup tapes with the DLT drives on Vortex

For Example:
	cd /home/vraid2/scratch/istairs/bcpm2

	ls S22[78]*.bcpm2 | xargs -n 1 tar cvf /dev/rmt/2hn > 
		do.fill.GC_020815_tape19a.out &

	ls S22[78]*.bcpm2 | xargs -n 1 tar cvf /dev/rmt/3hn > 
		do.fill.GC_020815_tape19b.out &

	NOTE:  Those last two commands should be on a single 
	line each (and 2 DLTs are required in the DLT drives obviously).
Modify the above for your situation.

Also note advice on Using the DLT drives on vortex

Comments, inaccuracies and suggestions for improvement to
Ingrid Stairs
last updated on 2003 Sept 4 by Glen Langston