How can I control Sierra Instruments MFCs using LabVIEW without the needed drivers?

[RavensFan]

Have you download the Modbus library from here?  http://zone.ni.com/devzone/cda/epd/p/id/4756

I would have thought one of the earlier links Ben posted would have been this.  But it doesn't look like it.  The Modbus example relies on this library.

[s.garcia]

Hey Ravens Fan:

I actually have downloaded the Nodbus library but I don't understand it fully. Quick question on that: Do the Master and Slave VIs go into my VI, or do I modify the existing Modbus VIs with mine?

I was looking at the MB Ethernet Master Example.vi and MB Ethernet Slave Example.vi, and I don't know how to relate these VIs to my VI (with VISA commands and such). I still haven't read any literature about it so I can't really say that I don't understand, but maybe a simple preview would be good.

Any help is appreciated. Thanks.

-Sergio

[RavensFan]

You would put the MB Serial Master Query VI as a subVI into your main VI.  You would wire up the appropriate connectors for VISA resource, serial parameters, and the Modbus command.

Overall, I don't like the example VI because it uses those horrible stacked sequence structures.  But if you look in frame 1 of the outermost structure, you will see an inner sequence structure with frames 0..4.  Cycle through those frames and you'll see different examples for how the MB Serial master Query VI is used for different types of messages.

[bfisher]

Did you get the drivers to work?  I have the same mass flow controllers, but the CRC isn't getting calculated correctly.  So, I can read the flow, but I can't change any settings.  Please let me know if you were able get your working.

Thank you.

Brandon