Negative terminals on connector block

[AlexG22]

Hello, this is a really silly question, but after using my DAQ card (NI DAQcard 6024E) with my connector block (SCC-68) for over a year with NRSE inputs, I now need to connect differential inputs. However, the connector block does not have any negative terminals.

Say I want to configure channel one as an input in CVI. I use this code to configure channel AI0 as a differential input:

DAQmxCreateAIVoltageChan(acqTaskHandle,chan,"pIn", DAQmx_Val_RSE,-.05,.05,DAQmx_Val_Diff ,NULL);

  -in this case chan is Dev1/ai0

I need to connect the signal terminals to AI0+ and AI0-, but AI0- is not on the connector block, just AI0. What am I supposed to do?

Thanks in advance,

Alex

[Dennis_Knutson · Accepted solution]

When you select differential, half of the inputs are used for the negative input. You pair ai0 with ai8, ai1 with ai9, ... ai7 with ai15, ai16 with ai24, etc. When you create the channel, you only specify the first of the pair. the driver will make the connection to the second pin.

Message Edited by Dennis Knutson on 06-08-2009 04:03 PM

[AlexG22]

Thank you for the quick reply.