IO-ATC8 Thermocouple problem

[Everton Luiz]

Hello!

I have a problem with an IO-ATC8 module using a type J thermocouple.

It worked for years, until one day the T3 input simply started to show *** instead of the current temperature.
The MI responsible for the T3 nput shows 32767, which indicates Greatly above or below the input range.

I did the basic troubleshooting, replaced the thermocouple with a new one, tried to use a jumper to get the ambient temperature, none of it worked.
Then I replaced the module with a brand-new one, it didn't work either. I didn't change the module's internal jumpers.

The module's "run" light is on. There isn't any "Out of range" light on.

The program worked for years, and it wasn't me who did it, I do have the backup but I'm not sure it is the same that is currently in the PLC.

PLC:
- Vision V1210 - V200-18-E2B.

Modules (They are connected in this order):
- EX-A2X
- 2x IO-D16A3-R016
- IO-TO16
- IO AO6X
- IO-ATC8 - Using all 8 inputs, T3 has the issue.
- IO-ATC8 - Using 4 inputs, no issues.
- Using Type J Thermocouples.

There is 12 Thermocouples, only 1 has the issue.

Sorry for any mistakes, english isn't my first language.

Thanks in advance

Everton

[Ausman]

I'd first be unplugging and reinserting ALL the ribbon connections b/n the PLC and all the I/Os.  If they're stacked side by side this can be a PITA.  I don't think this will fix the issue, but other basics first.

And what's the wrinkling on the cover?  If it's the actual display then it might be a problem, but I think it's a clear panel in the enclosure?

[Everton Luiz]

1 minute ago, Ausman said:

I'd first be unplugging and reinserting ALL the ribbon connections b/n the PLC and all the I/Os.  If they're stacked side by side this can be a PITA.  I don't think this will fix the issue, but other basics first.

And what's the wrinkling on the cover?  If it's the actual display then it might be a problem, but I think it's a clear panel in the enclosure?

I'll do that ASAP.

That's just a plastic cover, it is really dusty there. The display is normal.

Thanks for the reply.

Everton

[Ausman]

6 hours ago, Everton Luiz said:

That's just a plastic cover, it is really dusty there.

Ok.  Just ensure it can never touch the screen.  However, it looks like it is being pushed "through" to work the screen.  Tiny not wanted  touch registrations from worn protectors or even the protective membrane left in place and gradually perishing have caused issues.

Good luck.

[Gabriel Franco]

Connect the new themocouple directly to the IO-ATC8 and verify the results. Since replacing the analog module didn´t solved the issue, it may be a field wiring problem

.

[Everton Luiz]

13 hours ago, Ausman said:

Ok.  Just ensure it can never touch the screen.  However, it looks like it is being pushed "through" to work the screen.  Tiny not wanted  touch registrations from worn protectors or even the protective membrane left in place and gradually perishing have caused issues.

Good luck.

Ok, I'll make sure it doesn't touch the screen. Thanks.

 

 

4 hours ago, Gabriel Franco said:

Connect the new themocouple directly to the IO-ATC8 and verify the results. Since replacing the analog module didn´t solved the issue, it may be a field wiring problem

.

Yesterday I connected a brand new TC directly in the T3, the issue persists. I swapped the T2 TC with the T3, and the issue persists. I don't think it's a field wiring, but I'll check everything just to be sure.

Thanks for the reply.

Everton

[kratmel]

Analyzing your problem and your way of finding a solution, I can point out  facts:

1) The problem is related to a faulty connector, as Ausman rightly noted (use new connector from new module for test).

2) If replacing the connector does not help to solve the problem - you have two faulty modules - the one that worked in the system from the beginning and the new one that you installed. The above method of connecting the new temperature sensor to the new module is only good if you have not connected the old wires to the module before. Only in this way will you prove to yourself that everything is fine with the program and the controller. Since you replaced the old module with a new one with old leads, there is a chance that bad leads and shorting them to high heater voltage could have caused the new module to fail.

3)  it is most likely that you are miscalculating the number of the analog input in relation to the image in the picture of your PLC. That is, you have another sensor that is faulty, and you are trying to repair the one that is either not working and disconnected or on the wrong module. This often happens - check yourself, maybe a faulty T3 on the second one.