This is the Siemens 6ES7138-4CA80-0AB0, a SIMATIC DP Power Module PM-E RO for the ET 200S distributed I/O system. It provides a 24 V DC power feed with integrated diagnostics, handling the power distribution to the electronic modules in the slice. The part draws 600 mW typical power loss, which is the internal dissipation you budget for in the cabinet thermal calculation — not the load current passed to the field.
Physical fit and slot assignment
The module measures 15 mm wide, 81 mm high, and 52 mm deep. That 15 mm slice width is the standard single-width ET 200S footprint — it occupies one slot on the terminal rail. The 52 mm depth means it sits flush with the backplane bus; no extra clearance behind the DIN rail beyond what the rest of the ET 200S assembly requires.