[prev in list] [next in list] [prev in thread] [next in thread] 

List:       comedi
Subject:    RE: high channel count data acquisition
From:       "Caleb Tennis" <caleb () aei-tech ! com>
Date:       2003-02-05 12:55:13
[Download RAW message or body]



> We are looking to construct a data acquisition system that would have to
> acq. data from 100-400 channels of (slow period) analog values.
>
> What is the general or specific experience folks have had with
> platforms/hardware for this type of application?
>
> Single and differential acq. would be nice. As would use under Linux or
> other unix variant (linux preferred...).

For economic reasons I assume you'll want to use some kind of multiplexed
device to accomodate that many channels.

We use National Instruments's SCXI modules, which combine 32 channels into
one multiplexed module, and you can span multiple modules inside a chassis.
We use comedi with the SCXI patch and some other hacks in order to make the
system aquire as desired.  SCXI is a bit pricy, but definitely less
expensive than attempting to buy standalone DAQ cards to support big channel
counts.

You may also want to look at NI's Fieldpoint, or Automation Direct's Field
IO.  They are scalable modules that you can chain together to get the
desired # of channels, and they talk back to a computer either using Modbus,
Devicenet, Ethernet, etc.  We also use them (the Field IO) with linux using
RS485 cards.

I hope that gets you started.  Feel free to contact me if you have more
questions.

Caleb


_______________________________________________
comedi mailing list
comedi@comedi.org
https://cvs.comedi.org/cgi-bin/mailman/listinfo/comedi
[prev in list] [next in list] [prev in thread] [next in thread]