SCXI-1313a No Configuration (gain) Settings in Measurement and Automation Explorer

[chassan]

Hello,

QUESTION:

Please help.  What do I need to do to my system to be able to set the 1125/1313a to read over a +/-50v range?

PROBLEM DETAILS:

I have an SCXI-1125 with a 1313a attenuation module that is being digitized by a PXI-6251.

I create my daqmx tasks inside my program.  I want to set the max/min range for the signals coming in to the 1125/1313a to +/-50v.  However, I get an error from daqmx saying that the min/max is limited to +/-10v.

Furthermore, I don't see any way in MAX to set the attenutaion of the 1313a or the gain of the 1125.  MAX actually displays a message box saying that there isn't any required configuration for the 1313a.

Setup:

LabVIEW 8.6

MAX 4.6.2f1

DAQmx 9.0.2

Windows 7 Pro - 32-bit

Best Regards,

Chris

[Efrain_G · Accepted solution]

Dear Chris,

You might find useful to look at the following Knowledge Base so that you can find more details about what I am about to explain:

http://digital.ni.com/public.nsf/allkb/B138E2AA836B5354862570380073EA60?OpenDocument

The SCXI 1313a is an attenuator module that is used to reduce your voltage input levels so that they fit in the voltage input range for your DAQ board. When you use DAQmx in LabVIEW you don't need to worry about setting the +/- 50v range because it will be scaled automatically. You just have to choose any given voltage range that is valid for your specific DAQ board (+/- 10 v) in this case. 

It is for this reason that when you go to MAX to try to configure the attenuation, you get a message that tells you that you don't need to do it since the scaling is done automatically.

[chassan]

Hello Efrain G,

Thanks for the information.  I am aware of the purpose of the SCXI-1313a module, but this is the first time that we are using it; historically we have used an SCXI-1327 to perform the attentuation.  The SCXI-1327 requires a the attenuation to be set via a physical switch and then the SCXI-1327 setup in MAX must be modified to reflect the physical settings.

I see what you mean about the 1313a.  In my LabVIEW program when I create my ai channel, I just set the "min" and "max" inputs to +/-50V and the scaling of the 1327 and the gain of my ai card (PXI-1125) are configured automatically.

Thanks again.

Chris