Re: xspress3 internal triggering issue

[Matthew Newville via Tech-talk <tech-talk@aps.anl.gov>]

Hi Keith,

 

The xspress3 (or, now “older xspress3”) will stop counting a single frame and overflow its scaler clock values at 53.68 seconds (2**32 ticks of its internal 80 MHz clock).   But you can do multiple (16348, typically, can be changed in the IOC startup) frames with dwell times up to that value.

 

I believe the newer xspress3 Mk2 has a 200 MHz clock, but I do not recall whether the limit of 4G bins has been increased.

 

--Matt

 

 

From: Tech-talk <tech-talk-bounces@aps.anl.gov> on behalf of Keith Surrena via Tech-talk <tech-talk@aps.anl.gov>
Date: Tuesday, October 7, 2025 at 2:10 PM
To: tech-talk@aps.anl.gov <tech-talk@aps.anl.gov>
Subject: xspress3 internal triggering issue

I can no longer perform internally triggered data acquisitions with one of our 5 channel xspress3 units with dwell times that exceed 50 seconds. Last week I had set up a user that was doing 100 sec exposures with a weak source but over the weekend the IOC would stop the acquisition short, typically at around the 45 second mark, if not sooner. I have cycled all of the relevant hardware and controllers but the issue seems to persist. I can still seem to do long dwells with external triggers, but I appreciated the simplicity of utilizing internal triggers for the setup. Any thoughts?

 

Keith Surrena

Research Support Specialist

Cornell High Energy Synchrotron Source