Siemens SIMATIC S7-1200 - Page 1474

Technical specifications
A.11 Thermocouple and RTD signal modules (SMs)
S7-1200 Programmable controller
1474 System Manual, V4.2, 09/2016, A5E02486680-AK
Table A- 165 Diagnostics
Model
SM 1231 AI 4 x 16 bit TC
SM 1231 AI 8 x 16 bit TC
Overflow/underflow
1
Yes
Wire break
2, 3
Yes
24 V DC low voltage
1
Yes
1
The overflow, underflow and low voltage diagnostic alarm information will be reported in the analog data values even if
the alarms are disabled in the module configuration.
2
When wire break alarm is disabled and an open wire condition exists in the sensor wiring, the module may report ran-
dom values.
3
The module performs wire break testing every 6 seconds, which extends the update time by 9 ms for each enable
channel once every 6 seconds.
The SM 1231 Thermocouple (TC) analog signal module measures the value of voltage
connected to the module inputs. The temperature measurement type can be either
"Thermocouple" or "Voltage".
● "Thermocouple": The value will be reported in degrees multiplied by ten (for example, 25.3
degrees will be reported as decimal 253).
● "Voltage": The nominal range full scale value will be decimal 27648.
Table A- 166 Wiring diagrams for the thermocouple SMs
SM 1231 AI 4 x TC 16 bit (6ES7231-5QD32-0XB0)
SM 1231 AI 8 x TC bit (6ES7231-5QF32-0XB0)
Note: Connectors must be gold. See Appendix C, Spare Parts for article number.
① TC 2, 3, 4, and 5 not shown connected for clarity.