Experimental Physics and
Industrial Control System

"Mark Rivers" <[email protected]> · Thu, 23 Feb 2006 12:53:55 -0600

John,

I do exactly what you are trying to do with the Ip330 16-channel ADC.  Is that the Industry Pack ADC that you are using?

I put my data in mca records, rather than waveform records, but the principle is identical.  The Ip330 generates interrupts at a few kHz, and I put the 16 values into 16 MCA records.  The device support will do averaging, so that I can store at new point in the MCA record every reading, or average N readings before storing the new point.

The current implementation of this uses an "asyn" driver, using the callback mechanism provided by asyn.  There is device support for mca records (waveforms), ai records (averaging ADC), and epid records (for fast PID feedback).

The source is on the Web at
http://cars.uchicago.edu/software/epics

in the mca and ip330 modules there.

The current version is for 3.14.8.

There is still 3.13 support available, and in fact I just noticed that the documentation is still for 3.13.  The 3.13 version uses the Message Passing Facility (MPF), rather than asyn.

Mark

________________________________

From: John Dobbins [mailto:[email protected]]
Sent: Thu 2/23/2006 11:40 AM
To: EPICS Tech-Talk
Subject: Looking for Application Example

Dear All,

I want to create the following application in EPICS. I have a sixteen
channel industry pack ADC that I will be using in a VME crate with an
MVME162. EPICS version 3.13.10. I want to read the ADC at ~ 1.4 kHz and
record waveforms lasting 5 to 10 seconds. As this is faster then I can
imagine record processing taking place I assume I need to create device
support that creates a task which runs at 1.4 kHz, maintains data
buffers and periodically lets a waveform record (?) know that more data
is available (I'd like to be able to see some of the data before the
total acquisition is complete.)

Does anyone have code for something resembling this that I could look at?

Thanks,

John Dobbins
Research Support Specialist
Lab for Elementary Particle Physics
Cornell University

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System