SIMATIC S7-1200, digital I/O SM 1223, 16 DI/16 DO, 16 DI DC 24V, M-/P-reading, 16 DO, M-switching (sinking output), NPN transistor 0.5A SIMATIC S7-1200 Basic Controller - flexible thanks to a wide range of communication options. With signal modules, you can adapt the configuration of your SIMATIC S7-1200 (except CPU 1211C) to suit your individual requirements. A range of digital and analog input, output and mixed modules is available for this purpose, including fail-safe versions. This fine-grained design option saves you space in the control cabinet and optimizes your hardware costs.