daq_ctrl Process

The run control program (CTRL) coordinates all activities in data taking and gives an operator the full control over entire DAQ system. This is a GTK+ [6] program which provides a graphical interface shown on Fig. 3.

Figure 3: Run Control Window.

At the top it has a menu bar with four menus:

• General - general commands: Startup - to startup the DAQ system, Shutdown - to shutdown the system, Quit - to quit the program.
• Other - mixture of different commands:
  • Edit logfile. Usually all operator actions and changes of the run state are written in a log-file located in the $DAQLOG directory. Operator can manually edit the log-file. Warning: after finishing of the editing session don't forget to exit the editor, otherwise, there is a danger of discrepancy between the edited file and real log-file.
  • Clear messages. If the operator feels a need to clear all information messages in the ``message'' window, select this menu entry.
  • Change tape. If the operator wants to change the tape without shutting down the DAQ system, he should stop the run and select this menu entry.

• Processes gives manual control on the DAQ processes to experts. The operator can kill or restart them.

  By default, at the start of each run the program connects to the trigger program and requests the trigger parameters. This feature also can be switched off from this menu.

  Similarly the connection to the DAQ database can be switched off.

• Help - contains one entry (Browser) which starts HTML browser containing useful information.

The main window can be divided on five parts. The first part contains run related information: run type (e.g., PHYSICS), run state (e.g., RUNNING), run number, number of recorded events and buttons to start, stop, pause and resume the run.

An extract of trigger information is in the second part.

The third part describes recording: recording media (none, disk only, tape only, both disk and tape), VID (Visual IDentifier) of tape if any, recording state.

The fourth part is about the state of the processes running on the main machine. There are four processes on the main machine: daq_main, daq_fe, daq_rec and daq_mon.

The fifth part is the ``message'' window.

Possible states and their color coding is shown in the Table 9.

Table 9: Color coding of object states.

Color	Meaning	Comments
white	item is DISABLED	used for daq_rec and daq_mon
black	item is DEAD or not started	everything in this state when the system shuted down
darkblue	item is READY to start
green	item is RUNNING and data are arriving
cyan	item is IDLE (running but there has been no data recently)	used for the daq_mon process only and indicates that there is no connection to the monitor daemon either because of problem in the daemon or because nobody wants to monitor data
tan	item is PAUSED
brown	item is STOPPED
yellow	item has a PROBLEM
red	item has returned an ERROR status

The daq_ctrl process writes three log-files in the directory $DAQLOG. They are DAQ_date_time.log containing all messages from the message window plus some additional information, daq_ctrl_run.cfg with the last run number, and daq_ctrl_tape.cfg with the information about the last used tape.