thermopcouple f4-08-thm-n

[Harvey]

New to direct soft.  I need to drive the input high if there a thermocouple is disconnected or shorted. any ideas

[Gene Bond]

Forgive me, but I've not used this card, but couldn't you do do a couple of compares that are out of your normal range for alarms? Seemsif the T/C is shorted, the register would read very low, surely lower than normal for the process, and if it's open, it should read very high...

Again, maybe not applicable, but it may help.

[b_carlton]

The manual defines that there are "Broken Transmitter Bits".

As far as 'shorted', Gene's suggestion to test against any possible normal measurement is a good one. Be aware though that a shorted thermocouple - the two leads shorted together at some place other than the normal measuring end - will measure the ambient temperature at the shorted point.

[Harvey]

Open it is reading low, if I unwire the t/c it will read 92 deg what I would like this be a read high so the heater does not keep trying to heat.  Other plc cards I have used have a way to configure this; I have not worked much with direct soft.

[b_carlton]

I repeat:

The manual defines that there are "Broken Transmitter Bits".

It's not a function of Directsoft. It's a function of the thermocouple card. Read the instructions carefuilly.

[Harvey]

 yes it is "Broken Transmitter Bits"in on the f4-08thm not the -n. On the f4-08thm-j card it is to go high same as burned out thermocouple this is staying at 95 deg when the termocouple is unplugged. 

[Controls Guy]

There is no F4-08THM-N listed as a part number on the website.

[b_carlton]

The 'F4-08THM-N' is a shorthand for either of the older cards F4-08THM-J or F4-08THM-K which were single single type thermocouple specific. The (I believe) newer F4-08THM accepts a variety of thermocouples.

[Controls Guy]

Oh, sorry, I assumed it was a module specific to Type N thermocouples analogous to the J and K-type cards.

[Harvey]

My understanding is with the F4-08THM card you can set up each channel for a different type of thermocouple with a jumper, thank you for all the help and input.