Wiring torque sensor on NI 9205

[AntonBolander]

Hi,

I would like to wire a torque sensor (only the torque signal will be used) to a NI 9205  module. The pin description for the torque sensor are as follows:

I was thinking of using the module in differential mode so i thought I just connect signal + and - as below (apart form the power supply to the sensor):

Pin C to AI0

Pin D to AI8

But looking in the manual of the NI 9205 that option doesn't really exists. The closest seems to be the connection below:

And then I wondered what will the COM be connected to? Power supply 0V? Or "true" ground? Since there will be several sensor I guess it cannot be signal 0V but it looks to me that is what is done on the picture from the manual?

[sfrosty]

Curious: Is signal ground connected to Supply gnd or the housing of the torque transducer. My suggestion would be to connect true differential, C & D, like you stated and see what results you get. If the results aren't accurate, I would connect signal together with supply gnd to com on the 9205. If there is still an issue, you may have to connect a bias resistor (maybe 100K) between signal gnd and com. There is a bulletin somewhere on the NI website regarding the installation and value of a bias resistor. There should be no ill affects regardless of your trials regarding the signal connections.

[AntonBolander]

The signal gnd (0V) is connected to supply gnd (0V). But I wounder why the option I suggested is not availbale in the manual, is it not good practice?

If you add an bias resistor then you would have to attache all the signal gnd (0V) form all sensors together right?

[sfrosty]

A great reference:

https://www.ni.com/en-us/support/documentation/supplemental/06/field-wiring-and-noise-considerations...

I hope this is helpful!