S7-1200 SM1222 Digital Outputs

S7-1200 SM1222 Digital Outputs is the Siemens S7-1200 signal-module branch for adding discrete output channels when the PLC already belongs in the S7-1200 platform and the next decision is how many field loads the station needs to switch. Compared with SM1221 digital inputs, SM1222 is the output-side family for driving relays, solenoids, indicators, or other discrete loads rather than reading incoming field signals. Compared with SM1231 analog inputs, it is the right branch when the task is on/off actuation instead of analog sensing or process-value acquisition. Keep this family in scope when the rack still needs more discrete output capacity and the controller platform is already settled. Read the product list by output count and output type first, then narrow by electrical interface, load behavior, and the exact cabinet or machine wiring plan.