SIMATIC S7-1200 G2, SM 1231 TC, AI 8x TC module, type J or K. SIMATIC S7-1200 G2 Basic Controller - flexible due to a variety of communication options. If you only need to expand your SIMATIC S7-1200 G2 CPU by a few inputs or outputs, signal boards are a good alternative to signal modules. Signal boards are directly plugged onto the front of the controller and are available as digital and analog input, output, and mixed modules. Therefore, signal boards also allow for subsequent expansion of the configuration without additional space requirements in the control cabinet.