USB 6008 temperature control

[Mantis]

Hello,

I was wondering if anyone could help me with the following:

I am considering to use the NI USB 6008 DAQ module for a PT-100 temperature control system.

I was wondering if the following would be possible?

My plan is to use a PT-100 element connected to a Wheatstone bridge and powered by a 12V DC power supply. The bridge is then connected to the USB module via the NI connectors. This is then duplicated as I want to measure 2 temperatures. Then, Labview will calculate the temperature and operate a relais with PID control, controlling some kind of heat element.

What is the input signal for the module though? The wheatstone bridge will give some kind of current value (4-20mA), does the module translate this into 0-5V? Or can this be configured otherwise? Thanks.

Regards,

Bart Gzik

[Mantis]

Anyone?

[Brian_Beal]

The USB 6008 only measures voltage.  You have to measure voltage across a resistor to get current.  A 250 ohm resistor will give you 1-5 VDC for a 4-20mA signal.