Enabling/Disabling Streams

Streams can individually or collectively enabled or disabled, meaning that the dp0 program runs as if the events were written out to tape, but the actual transfer to tape is not done.

There are two ways how streams can be enabled or disabled: A global enable/disable can be done on the dp0 main menu by pressing the push button at the bottom of the window. This will disable all the currently open streams. Alternatively one can disable/enable streams individually in the configuration window as described above.

One possible way of using this feature is the following: Imagine you are taking data to (possibly several) tape(s) and you want to make a short run to disk or trashcan. This can be done in the following steps:

• End the current run
• Disable all the streams (either one by one or all at once using the ``data taking enable/disable'' button at the bottom of the dp0 menu).
• push ``change configuration'' button
• press ``add stream'' button and define a new stream, e.g. stream name = crap, disk file = /scr0/bnlonl/oneday/test.dat triggers = ALL.
• open this stream
• start a new run: only the enabled streams will now get data
• end the run
• close the stream ``crap''
• enable all the streams to tape
• start a new run with the standard online pass 0.