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.

Hybrid module SM 1234 
Analog hybrid modules offer digital inputs and outputs in one module with a small footprint.

Energy Meter Module SM 1238
The Energy Meter Module SM1238 is the ideal entry into machine-level energy management. 
The space-saving expansion module is just 45 millimeters wide, and can be used to record energy flows simply and precisely, directly on the machine. The measurements are processed directly in the CPU, and visualized with a Basic or Comfort Panel. The SM1238 Energy Meter module records measured electrical values, such as voltages up to 480 V AC, in a 1 or 3-phase network with a direct connection but without a transformer. The user can freely adjust the diagnostic parameters for over and undervoltage, overload, tolerance value and tolerance time. An external 1 or 5 ampere current transformer with a conversion factor of up to 10,000 is used to measure the current.