Siemens SIMATIC User Manual

Analog modules
6.11 Analog input module SM 331, AI 6 x TC isolated (6ES7331-7PE10-0AB0)
S7-300 Module data
414 Manual, 06/2017, A5E00105505-AJ
Wiring: Thermocouple with external compensation
With this type of compensation, the temperature of the terminals at the reference junction is
established using a Pt 100 Klima resistance thermometer with a temperature range of -145
°C to +155 °C (see terminals 35, 36, 39, and 40).
①
Thermocouple with terminal for external temperature compensation via copper wire at front connector
②
Backplane bus interface
③
Analog digital converter (ADC)
④
External cold spot comparison (ADC and current source)
Figure 6-33 External compensation
If no Pt 100 resistance thermometer is available, the reference junction can be read using a
thermoresistor module. The measured temperature values are then transferred to module AI
6 x TC via data record 2 (for details on the structure of data record 2, see the figure
"Structure of data record 2 for TC").

Siemens SIMATIC Specifications

General

Product type designation	SIMATIC
CPU	Varies by model
Memory	Varies by model
Input/Output	Varies by model
Communication	Varies by model
Programming Language	STEP 7
Operating Temperature	0°C to 60°C (varies by model)
Protection Class	IP20
Category	Programmable Logic Controller (PLC)