Hello, you are right I did the inversion between Min and Max, but even corrected the problem is not solved.

The Thermocouple is type J

OlivierHebb

Hello, you are right I did the inversion between Min and Max, but even corrected the problem is not solved.

The Thermocouple is type J

It seems that you have a very complicated problem.

Hello,

Just to inform you about the last news regarding the mentionned problem.

Which seem coming from wrong hardware base of the AI board, the one I'm currently using does not have the reference junction, so I need to buy the good one.

Order is in progress, I will let know asap.

Hello,

I'm pleased to inform and confirm that with the appropriate base-unit, everything is working better!!

OlivierHebb

Hello,

I'm pleased to inform and confirm that with the appropriate base-unit, everything is working better!!

Hi,

I have the same problem, can you tell me please, which base unit you selected to slove your problem?

Thanks a lot.

AMSAutomation

 

OlivierHebb

Hello,

I'm pleased to inform and confirm that with the appropriate base-unit, everything is working better!!

Hi,

I have the same problem, can you tell me please, which base unit you selected to slove your problem?

Thanks a lot.

 hi AMS Automation,

have a Look into the Manual Collection to get the information which BaseUnit is the right for your module.

See the Basic Information->decentral peripherie system chapter 3.1

hope this helps,

regards,

You discovered that the thermocouple was connected backwards; it had the wrong polarity.  Heating a thermocouple connected backwards drives the reported temperature downwards.  But you've corrected that.

1.  Somewhere, the internal "cold junction" needs to be enabled.   The lack of cold junction produces a reading that is too low by difference in the temperature of the terminal block and freezing point of water (0C).

2.  Siemens uses a 'base' unit that has to match the analog input card.  Is your base compatible with the AI card?

3.  If you can touch the tip of the thermocouple, it is not likely a ground loop created when a thermocouple junction or a ground junction is in contact with metal that has a ground potential different than the analog input.  A ground potential generates a ground loop which can drive the reported temperature in either direction.  Holding the thermocouple tip in the air while touching it rules out a ground loop because the tip is 'floating'; the tip is not touching metal that can have ground potential.  If the tip is spot welded to a pipe and you're touching it, then it can be a ground loop issue.