Experimental Physics and
Industrial Control System

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<== Date ==>		<== Thread ==>

Subject:	RE: USB ADC/DACs
From:	"Pawel Kowalski - BiRa Systems Inc." <[email protected]>
To:	"'Eric Norum'" <[email protected]>
Cc:	[email protected]
Date:	Wed, 5 May 2010 10:37:11 -0600

Thank you Eric,

The reason I want to do USB is so that I can connect it directly to a mini linux computer without needing an additional Ethernet port. Then this mini pc will have epics IOC running on it which will interface to the USB DAC/ADC and can then be accessed over Ethernet using process variables.

The link you sent looks interesting but I think 0-10V would be better since that’s the standard a number of power supplies seem to use. Any other suggestions would be appreciated.

------------------------------------

Pawel Kowalski

BiRa Systems Inc.

www.bira.com

Phone: 505-881-8887

Fax: 505-888-0651

Address: 2410 Midtown PL NE

STE A

Albuquerque NM 87107 USA

From: Eric Norum [mailto:[email protected]]
Sent: Wednesday, May 05, 2010 10:10 AM
To: Pawel Kowalski - BiRa Systems Inc.
Cc: [email protected]
Subject: Re: USB ADC/DACs

I'm surprised that you're hearing more requests for USB connections than for ethernet. The latter allows for much longer connections and is better supported by EPICS/ASYN.

In any case, a small PLC sounds like it would take care of this just fine.

How about something like (only 0 to 5V, but perhaps that's good enough):

PLC, plc direct, PLCs, Programmable Logic Controller, PLC's, Koyo PLC, CLICK PLC

Adding an FTDI USB/Serial adapter adds about $20.00

There are small PLCs in this price range with Ethernet, too.

On May 5, 2010, at 8:35 AM, Pawel Kowalski - BiRa Systems Inc. wrote:

Hello,

Based on feedback I got at the beam and instrumentation workshop this week I am trying to come up with a simple and cheap design to control analog power supplies. Nothing is set in stone and I just want to find what we would need to get to make this controller. I am trying to find a DAC/ADC that can be connected using USB to a soft-ioc running linux. I don’t need a lot of channels, 1 analog in and 1 analog out would be fine (2 of each would be preferred) and having a couple digital in/digital out channels would be nice too (but not required). The voltage will be 0-10V (if a bipolar DAC/ADC is available that would be great). I would probably need to have at least 16 bits of resolution on the DAC/ADC. The speed doesn’t have to be terribly fast from what I gathered. Cost is an issue (trying to stay under $200) but if something is out there that costs more than this I would like to take a look at it anyway.

I wonder if anyone in the epics community has worked with such a device and if they have epics drivers available. If epics drivers aren’t available I can probably configure something myself using ASYN if someone can point me to a good reliable device. Any suggestions would be greatly appreciated, thank you.