Using Ohaus Ranger scale with NI 9870 (cRIO)

[Nick_Greenway]

Hello,

I am using a NI cRIO-9074 data aquisition system with a NI 9870 4-Port, RS232 Serial Interface Module, and am programming with LabView 2012. I'm currently looking for a scale with an RS-232 output that I can plug into the NI 9870 to receive and store measurement data. I'd like to go with an Ohaus Ranger 7000 scale, model number R71MD3. However, looking at NI's list of instrumentation drivers, they do not have anything listed for this model, though they do have quite a few for other (seemingly older) Ohaus scales.

Are drivers not needed for this scale? Or is there a standard RS-232 that can be used? I'd like to ensure that this setup will work before purchasing the scale.

Thanks!

[cody_a · Accepted solution]

Using the 9870 in a cRIO essentially just adds 4 more COM ports to the cRIO, which you can interface with using NI-VISA.  Check this KB for more details.  Most "instrument drivers" are just an abstraction layer or wrapper for the low-level VISA reads and writes being performed.  If an instrument driver does not already exist, you can implement a simple one yourself using VISA.

In this situation, you'll simply need to look up the command/instruction set the device uses, and implement those using VISA reads and writes.  As long as the command set isn't too extensive, this is pretty simple and quick.

So, this setup will definitely work, you'll just need to take the time to implement the VISA commands yourself.

[Nick_Greenway]

Perfect, thanks for the explanation!

[Dennis_Knutson]

You should check with Ohaus to see if the command set is shared with any of its other scales.

[Nick_Greenway]

Good idea, will do!