Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Mon, 20 Apr 2015 20:42:47 +0000

> Since Measurement Computing didn't release a port of their control library in addition to the communications drivers, 
> all the command calls that the measComp driver relies upon need to be reverse engineered from the documentation.

I'm confused.  What about the Linux drivers here:

ftp://lx10.tx.ncsu.edu/pub/Linux/drivers/USB/

I downloaded that package, and there is a nice library for the USB-1608G, for example.  It has different functions from the ones in the Measurement Computing Windows library, but they appear to be quite complete.  I would think it would be pretty straightforward to re-implement my 1608G EPICS driver for Linux using that library.

Regarding the DACFlex library, this appears to have been abandoned by Measurement Computing.  This is from their Linux FAQ page:

Question:
Hi I've noticed that for a while the new USB devices I'm receiving info on are not being listed on the Linux page. Is the Linux support (DAQFlex etc) no longer being supported? The device I'm interested in currently is the USB-230-OEM.

Answer:
Regrettably, no new products will be added to our DAQFlex library. Support for existing hardware will continue. For an easier out-of-the-box Linux experience, we recommend using the MCC 3rd party drivers. Please see http://www.mccdaq.com/daq-software/Linux-Support.aspx for more details. Currently, the USB-230-OEM series is not supported by our Linux drivers. The hardware architecture of the USB-230-OEM series does not lend itself easily to Linux development. For that reason we have chosen to hold off with Linux development. For a low cost 16 bit DAQ device with Linux support, I would recommend one of our USB-1608G series products. Please see http://www.mccdaq.com/usb-data-acquisition/USB-1608G-Series.aspx

Mark

-----Original Message-----
From: Lang, Keenan C. [mailto:[email protected]] 
Sent: Monday, April 20, 2015 3:17 PM
To: Mark Rivers; Matt Rippa; [email protected]
Subject: RE: Measurement Computing Linux C Drivers

I had put development of porting the support to Linux on hiatus, but can try to finish things up now that there is a want. Since Measurement Computing didn't release a port of their control library in addition to the communications drivers, all the command calls that the measComp driver relies upon need to be reverse engineered from the documentation. This was a simple enough task for most of the calls, but the AIScan and AOScan commands are a bit tougher to match the expected behavior. I have C# source code for measComp's new control library (called DAQFlex), but the code base is enormous and a bit convoluted. As well, once all is said and done, the performance may be undesirable.

Keenan
________________________________________
From: Mark Rivers [[email protected]]
Sent: Sunday, April 19, 2015 8:46 AM
To: Matt Rippa; [email protected]
Cc: Lang, Keenan C.
Subject: RE: Measurement Computing Linux C Drivers

Hi Matt,

That Linux support is not new, it has been there since I started working on the drivers.  I was discouraged by this document for the Linux support:

ftp://lx10.tx.ncsu.edu/pub/Linux/drivers/USB/README_mcc_usb

The document is old (2008), so perhaps it no longer applies.  But it states that the fastest performance they could get was 50 kHz, which is an order of magnitude slower than the Windows drivers from Measurement Computing.

That being said, I believe that Keenan Lang from APS BCDA has been working on Linux drivers for these devices.  I have not yet seen any official release from him, but I have CC'd him on this message so he can respond directly.

I also believe that the accelerator group at APS got Linux support working for some models which are used for the APS vibration monitoring system.  Again, I don't think that have released their drivers.

Mark

________________________________________
From: Matt Rippa [[email protected]]
Sent: Saturday, April 18, 2015 11:18 PM
To: [email protected]; Mark Rivers
Subject: Measurement Computing Linux C Drivers

Hi Mark,

I was looking at your package for measurement computing
devices below. Their website now links to open source  Linux
drivers written in C. Have you seen this yet? And are you
planning to incorporate this into your existing epics support?

Thanks,
-Matt

http://cars9.uchicago.edu/software/epics/measCompDoc.html

http://www.mccdaq.com/daq-software/Linux-Support.aspx

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System