Guide to Data Taking in Hall A

Bob Michaels,     v4.1,     Jan 25, 2010

pager: (757)-584-7410,    e-mail:    rom@jlab.org

This file :  hallaweb.jlab.org/equipment/daq/guide_2daq.html

This is information about how to run DAQ and how to configure the trigger in Hall A. See also hallaweb.jlab.org for useful links such as the ROOT/C++ analyzer.

 I.  Where   to   Run   Things

Below is a table showing where to run the different codes using the public accounts adaq, atrig, and a-onl. The run coordinators should know the passwords.  

Where to Run Online Software in Hall A Counting Room

Code	Computer	Public  Account
CODA  Left HRS	adaql3	a-onl
CODA  Right HRS	adaql2	a-onl
Podd  ANALYZER	adaql4-10 (not 1-3)	adaq
HAPPEX DAQ	adaql5	apar
trigsetup	adaql1 or 2	atrig
xscaler	adaql4-5	adaq

For more info on running the spectrometer DAQ see the Hall A DAQ guide

Computers:   adaql5 is for running the HAPPEX DAQ. adaql2 and adaql3 is used for RHRS and LHRS DAQ, respectively. The 'compton' computer belongs to the Compton DAQ and should be avoided. The controls computer is hacsbc2. Sometimes adaql1 is used for Moller DAQ.   adaql4 - 10 are for running data analysis using Parity Analyzer "pan" or the HSS ROOT/C++ analyzer ``Podd'', but any computer where CODA is running should be avoided. Note the large amount of ``work'' disks where you may keep scratch files like hbook. The disks are /adaqlN/workM where N=1,2... and M=1,2,3...etc. Some PCs are also installed in 2nd floor cubicles. Priority for use goes to running experiments.

Most of the computers are maintained by Ole Hansen with Bob Michaels as a backup. hacsbc2 is maintained by Javier Gomez.

How to reboot workstations : Hit Ctrl-Alt-F1 to go to console mode, then Ctrl-Alt-Del. (i.e. hold down "ctrl", "alt", and the other button simultaneously)

 III.  CODA  

Detailed information about running the spectrometer DAQ in Hall A may be found in hallaweb.jlab.org/equipment/daq/guide2_2daq.html  for CODA 2.x setup (read this if nothing else).

Info about How to run HAPPEX DAQ during PREX.

Also available are documentation about the raw data structure (dstruct.html)   and FAQ's about deadtime (dtime_faq.html),   plus electronics deadtime.

IV.  Trigger

The spectrometer trigger was described in some detail in the OPS manual.   Here I give a superficial overview and describe how to download a new setup.   First, here are some simplified instructions to download and check the trigger:

hallaweb.jlab.org/equipment/daq/trigger.html.

During HAPPEX through PREX, there will be a variety of HRS triggers. The main ones are T1 (S0 detector) and T2 (absorption detector), but there will be others for PVDIS as well.

V.  Scalers and Scaler Display

``xscaler'' is the GUI that displays scaler data online. Normally xscaler is running on the hapc5 screen which is above the adaql2 console (in rack CH01A09). If not running, login as adaq, and type "xscaler" and follow the instructions it prints out. There are two versions (old and new), the new version is recommended but that's up to you.

 Scalers are read and injected into the datastream during a run and at the end of the run.  A file scaler_history.dat is maintained which is a complete history of scaler readings at the end of the run.  These files should be in ~a-onl/scaler.   An script runs on the online account which processes the scalers to make halog entries for end-of-run.