Moggie

Genuinely interested in where you got this information from? My search only returned that the S7CT EM231 was manufactured by CO-TRUST Technologies Co, (I agree that anything with CN is for the Chinese markets)

OK the more information the better. The maths is simple, your starting point was -130 degrees. You raise the actual temperature to 149 degrees as read by thermometer. -130 + 149 = 19 degrees. The real question still remans why does it read -130degrees to start with?? Have you tried reversing the connections of the TC, what does it read then? Also, What mV reading do you get from the TC when it is not connected to anything? (take the reading at the actual TC not at the EM231 when disconnected).

Sorry, I am confused. Where did the 19 degrees come from? I thought the error was showing minus temperatures? also your mV chart says its not available

What mV reading do you get from the TC when it is disconnected from the EM231 card? Have you a brand new TC that you can connect direct to the EM231 card, if so what temperature does it read and what mV do you get?

Your image is not very clear. Please check the dip switch settings. Your image shows switch 3 is down whilst the manual (and schematics) show it in the UP Position for type K But it is not possible to tell the correct position from your picture. Image from the manual shows ON position is up.

So we have very important information in that it is not original Siemens S7 200 system. It would appear that this CTS7 EM231 card is a PID control card as well as a Thermalcouple input card. Changing the PID settings should not alter the actual temperature readings. Have you an image of the dip switches on this EM231 card?

Where are you with this? Have you tried anything from my post?

What checks have you carried out so far? Please check as per this - https://www.electricalvolt.com/testing-a-thermocouple-with-a-multimeter/ Also - 1. For a reading that is wrong disconnect the TC and connect a link, what does the temperature indicate now for that channel? 2. Connect a TC direct to an input channel directly at the EM231, what does the temperature indicate now for that channel? 3. Are there any signal amplifiers or conditioners in the circuit? 4. Have you a copy of the electrical schematics? 5. What is the exact part number of your em231 card, it will start with 6ES7 xxx xxx xxxx 6. What temperature are you expecting to see on any channel? ie normal working range! 7. What TC type is connected? 8. Are the TC's all the same type? 9. For the EM231 TC card there are dip switches for settings what are they set to? 10. Have you a picture of the dip switches? 11.What mV do you read at the EM231 Connections with the TC Connected? 12. What mV do you read at the EM231 Connections with the TC Disconnected?

Manual can be found here https://www.omron-ap.com/products/family/1916/download/manual.html

This is from the manual for CP1L. You have to use the "First Scan" flag to set the card parameter, for 4 to 20mA you would use the Range Code 010. The above example shows the value for the entire 16bits. #800A = 1000 0000 0000 1010 It sets the card for 1x 0 to 10v & 1 x 4-20mA (or 1-5V) analog inputs and 1x -10 to +10V analog output. For 2 x 4 - 20mA inputs the bit pattern would be 1000 0000 0001 0010

Can you post your code for the set up of the card parameters?

Is this a new installation? Have you set the parameters for the analog card?

It depends on the output from the shunt. Usually they are marked with A/mV, ie 15 - 50A = 25 - 100mV. You will need to see what your shunt gives out and then with this information you can select the correct analog input for your PLC. In the PLC you would have to scale the input to display the "real" current.......

Try putting a normally closed of "BUSY" in series with "M0.7" in the "REQ" input

Have you looked at this ? - https://dl.weintek.com/public/MT8000/eng/FAQ/FAQ_77_Establish_iSeries_S7-1200V4.0_Communication_en.pdf