programming a thermocouple

[electrojef 0]

I need to turn on/off a fan using a thermocouple when water temp is 70F.This is the first thermocouple I've had to program. Can anyone provide me any info/examples on how to program this. Do I use a sub block. I think that what I'll use,not for sure.I hope i provided enough info.Thanks

[Crossbow 297]

You'll need the manual for the module, but it should be addressed as several 4x addresses. Each one would be an input signal to the PLC, and you can do whatever you need to in the PLC with that numeric value. Info on which PLC and which software would help us be more specific.

[electrojef 0]

I'm using proworx 32 and a AAI 520 card. I'm triing to figure out the best way to program. Using sub blocks I'Ve seen sub blocks used using 4xxxx registers,but i'm really not sure the best way to program.would you have any suggestions. Thanks

[Crossbow 297]

Program it for what? In the traffic cop you assign it addresses, and those addresses will contain the temperature data. Use it however you need to in your application. Again, what PLC platform? Momentum, Quantum? Check the manual for the module and it will tell you what addresses contain what data and what format it is. You could always post a copy of the program so we can see the traffic cop configuration to provide more detail, but it's all in the manual.

[electrojef 0]

Sorry, I may not be asking the question correctly. I'm fairly new to plc's.It is a momentum,and I know how to use the traffic cop to install the AAI 520 40 card.I found in the manual how to hook up the type J thermocouple to the device.This is the first one I've had to program.I guess I should have asked the question this way. I have seen in other programs where there using sub blocks in the logic to control tempertures. I'm wanting to turn on a fan when the temp is 70 degrees and turn off when it is below 70 degrees. Is there any way you could provide me with any examples of programming this in the ladder logic.Sorry for being so confusing,and I hope this make sense. Thanks for your help

[Crossbow 297]

The SUB instruction is sometimes used as a comparison, as the 984 ladder logic language is very weak on commands. Look up the SUB instruction in the Modicon Ladder Logic Block Library manual. It's not really doing any control, just a comparison.