Dear expert,

In Our plant in extruder application we have installed J type thermocouple in simatic manager hardware configuration i have selected J type TC-il but on HMI screen instad of showing abmbient tempreture(27-30degree) it shows 10-15degree lower value.

I have connected it as per diagrame in analog input module my analog input resolution is 13bit

Can any body tell me what could be the possible reason?????

Thankxx in advance

Which is CPU?

Which is AI module?

Have you configured correct type of thermocouples in AI modules hardware & PLC project?

How you scale AI?

Please check.

Dear sir i am using AI8*13bit(6ES7 331-7KF02-0AB0) analog input module to interface thermocouple and in input properties i have selected TC-IL and j type thermocouple.i have checked my programe it was properly scaled but still actual temp is not showing on HMI.

My cpu is 315-2DP

Please refer SIMATIC S7-300 SM331; AI 8 x 12 Bit Getting Started part 3: Thermocouples  application example, which will help you to understand wiring connection, settings of AI module, hardware configuration & programing of thermocouple to AI module of PLC.

Hope this helps.