Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Mon, 10 Mar 2014 13:15:22 +0000

Hi Matthias,

As you may know, the SIS3820 is increasing becoming the "scaler of choice" for the EPICS community, especially now that the Joerger scaler is no longer available.

The SIS3820 is much more useful than the Joerger because it can be used for "on-the-fly" experiments.  The 3820 can be used as the timing source to trigger detectors.  It can use its internal clock and be the timing master,  or it can be used as a pulse divider from stepper motors pulses, for example, and generate detector triggers that way.  An increasing number of experiments are being done in this manner.

There is one limitation of the SIS3820 for this application that I would like to propose could be overcome with what I hope is a relatively simple firmware upgrade.  The problem is that the CIP output (Output 5 in all output modes), which is what we use to trigger detectors, is not configurable.  It is a negative pulse (5V going to 0) of a duration less than 1 microsecond.  This is not compatible with many detector trigger requirements.  We often need to use additional electronics to invert and/or stretch this pulse.

I would like to propose that the firmware be enhanced to provide:

- Programmable polarity of the CIP/LNE output
- Programmable pulse width of the CIP/LNE output

Is this something you would be willing to consider?  If you add it to the firmware I will add it to the EPICS driver :-)

Thanks,
Mark

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System