Does anyone have sample code showing how to add input filtering on Thermocouple inputs.
I have followed all the required hardware installation requirements and still get irratic readings.
I see fluctuations of 20-25F even with the inputs shorted which should show a stable ambient temperature.
The T/C module is in slot 1 of a 10 slot base with a 350 CPU.

I'm no guru for PLC Direct, but if shorted terminals fluctuate 20 F then you've got someting really flaky in your setup. Just mho.

As far as filtering the simplest filter on an analog input is to add a percentage of the new and 1 - percentage of the old to get the filtered reading. Math looks like follows:

Filtered Reading = (0.25 * New Reading) + (0.75 * Previous Filtered Reading)

You apply this logic after each new reading. The larger the percentage of new reading the less filtering.

Are you shorting the inputs at the terminals or at the end of the thermocouple wires? Do you have the cold junction input hooked up? Is is reading stable?