Loading and Checking the Hall A HRS Trigger

Robert Michaels, rom@jlab.org, Jefferson Lab Hall A, Apr 2002

This file: hallaweb.jlab.org/equipment/daq/trigger.html

The Hall A HRS trigger system is remotely configured by CAMAC modules. The main change during the experiment is in the delays required to adjust the timings of triggers which change with momentum and particle ID relevant for coincidence setup only. Of course for single arm running one may just use the defaults, but it may still be a wise investment in 2 minutes time to download in order to make sure of the state of the modules. If the power is turned off, the CAMAC modules certainly must be reprogrammed.

SIMPLE DOWNLOADING INSTRUCTIONS:

To download the trigger, first login to the ADAQ Linux box adaql1 or adaql2 (and no others) as ``atrig'' account. (E.g. ssh adaql1 -l atrig). The Run Coordinator should know the password. Type ``trigsetup''. A self-explanatory graphical user interface pops up, where if you are in a coincidence experiment setup you must enter the momenta and particle ID's and then press "Download" and WAIT for it to finish and do not press Ctrl-C. However, for single arm running like Spin Duality or GDH, just press "Download" with the defaults, and WAIT for it to finish and do not press Ctrl-C. The user should look for suspicious error messages in the window from which trigsetup was launched, e.g. to check if connection to the crate is ok.

EXPERT MODE:

CHECKING AND RECORD KEEPING:

FURTHER DETAILS:

One source of information on the trigger is in the Hall A Operations Manual though it tends to be out of date. hallaweb.jlab.org/document/OPMAN/index.html.

Also, here are detailed notes, which generally get updated just before we run when the final trigger configuration is settled: hallaweb.jlab.org/equipment/daq/trigsetup_coinc.html.

And here are some other relevant links about DAQ and trigger in Hall A.

The trigger manager software is based on code written by Tim Smith and Jeff Vieregg at MIT for the BLAST trigger. It is written in a framework of C++ and ROOT.

R. Michaels -- e-mail: rom@jlab.org