From: Frisch, Josef C.
Sent: Wednesday, July 17, 2002 5:42 PM
To: Luchini, Kristi
Subject: Joerger trigger problem.

Hi Kristi

I don't know the set of changes that put us in the following state, but where we wound up was....

The Joerger digitizers should be triggered at 60Hz until a trip is detected. On a trip, the triggers should be disabled in hardware until the Joergers are read out.

The problem occured when the hardware that should have disabled the triggers was not operating properly. It has been fixed. 

This can be tested in the future by looking at the trigger lights on the modules and then causing a RF trip. The lights should be on steady (60Hz) normally, and should turn off if there is a trip until the modules are read out.

If the triggers are not disabled, the first module may read correctly, but other modules will not read before new data is acquired and the outputs will not be correctly synchronized. 

Sorry about a hardware problem being interpreted as a software problem.

--- Joe Frisch