Product Name:  Siemens S7-1200 PLC

Brand Name: Siemens 

Model:6ES7231-4HD32-0XB0

SIMATIC S7-1200

 Analog input SM 1231

4 AI, +/-10 V, +/-5 V, +/-2.5 V, or 0-20 mA/4-20 mA, 12 bit+sign (13 bit ADC)

Analog inputs for SIMATIC S7-1200

The SM 1231 analog input signal modules convert analog signals from the process into digital signals for internal processing by the SIMATIC S7-1200.

With extremely short conversion times

For connecting analog actuators and sensors up to 14 bit resolution and different input ranges without additional amplifiers.

For solving even more complex automation tasks. Updating of the user program is extremely simple.

RTD-Module SM 1231 
The SM 1231 RTD modules enable temperatures to be measured with high precision using resistance-based temperature sensors. 
The most popular resistance-based temperature sensors can be used. They are connected directly to the module without amplifiers and all RTDs must be of the same type. The sensors can be connected with 2, 3 or 4 cables.

Thermocouple modules SM 1231 
The SM 1231 thermocouple modules enable temperatures to be measured with high precision using established thermocouples. In addition, low level analog signals in the ±80 mV range can be recorded. Four thermocouples each of types J, K, T, E, R, S and N can be used. They are connected directly to the module without amplifiers. 
For maximum possible measurement and repeat accuracy, the thermocouple modules should be mounted in locations with low temperature variations.