Signal boards are connected directly to the front of the CPU. They can be used where space is limited or if only a few additional inputs/outputs are required.

• Each S7-1200 CPU can be modularly expanded by a signal board.

• This does not increase the mounting space required for the controller.

• The portfolio includes digital inputs, digital outputs, mixed digital IOs, analog inputs and analog outputs. 

Or browse through the image gallery to see how easily signal boards are mounted:

The SM 1221 digital input signal modules convert the level of the external digital signals from the process to the internal signal level of the S7-1200.

• For flexible adaptation of the controller to the task at hand. This avoids superfluous investment. Modules with 8, 16 and 32 input/output channels are available.

• For subsequent extension of the system with additional input. If the task is extended subsequently, the controller can be upgraded with one of these digital modules. Updating of the user program in TIA Portal is extremely simple.

The portfolio comprises 12 different modules.

Digital input module SM 1221 
The SM 1221 digital input signal modules convert the level of the external digital signals from the process into the internal signal level of the S7-1200.

Digital output module SM 1222 
Modules with 24 V DC outputs, relay outputs or relay outputs changeover.

Digital hybrid module SM 1223 
Digital hybrid modules offer digital inputs and outputs in one device with a small footprint.

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.