SCB 68, PCI 6024e question

[TopKid]

I am getting erratic temperature readings using the pci-6024e and the scb68.

I did the following steps.

1. Set the switches to: Temperature sensor enabled on differential CH0. Accessory power on.

2. I believe this connects the CJC internally to ACH0 and ACH8. I don't need to connect anything else here right?

3. Next I connected my thermocoule to pins 30 and 63 (ACH3 and ACH11). I also connected a 10K bias resistor between ACH11 and and pin 29 (AIGND) for ground reference.

I think all my steps are correct here. I appreciate any comments. The analog input on the same channel works fine.

I tested this in MAX with built in CJC and correct thermocouple type.

Can you give me other ideas for things to check my setup?

Thanks

Sharif

[Jarrod_B.]

Hello Sharif,

First of all, please make sure that you have followed all of the steps listed in the KB How Do I Use the Cold Junction Compensation on the SCB-68?.  In particular, make sure you have selected the SCB-68 as the accessory on your PCI-6024E and selected "Temperature Reference Enabled."

If you have done that, try connecting the thermocouple to different channels and see if any of them give you a better reading.  Also, try connecting different thermocouples to the same channel and see how that affects the readings.  All of this information will help narrow down the cause of your erratic readings.  If none of this helps, please let us know how erratic your measurements are, and we can look for other causes.

Thanks,

[TopKid]

Thanks for the response.

It turns out the cable I was using was faulty. Argghh.

Thanks for the tip though.