8-channel 24V DC transistor output slice for S7-1200 racks
The Siemens 6ES7222-1BF30-0XB0 is an SM 1222 digital output module that fits the S7-1200 backplane, delivering 8 transistor-switched outputs at 24 V DC, each rated 0.5 A continuous with resistive or inductive loads. Each channel switches on in 50 µs and off in 200 µs, fast enough for valve banks and small contactor coils without missing edges.
Electrical and thermal limits that govern the BOM line
Per-channel current is capped at 0.5 A for both resistive and inductive loads; the module has no internal short-circuit protection, so each output must be fused or protected externally per the installation rules. Typical power loss is 1.5 W; the module draws its backplane power from the S7-1200 bus and does not require a separate load supply beyond the 24 V DC field power.
Mounting and wiring constraints for panel integration
The module is 45 mm wide, 100 mm tall, 75 mm deep — it occupies one S7-1200 slot width and snaps onto the DIN rail with the standard SIMATIC locking lever. A front connector (ordered separately) is required for field wiring; the module supports unshielded cable runs up to 150 m and shielded runs up to 500 m.
Lifecycle, approvals, and sourcing posture
Carries CE, FM (Factory Mutual) for hazardous-location use, and RCM (Australia/NZ) approvals — covers most global panel certifications.