2 outputs, 0.5 A per channel, 24 V DC
The Siemens 6ES7122-1BB00-0AA0 is a 2-channel digital output module for the SIMATIC S7-1200 PLC family. Each output is rated for a signal "1" current of 0.5 A at 24 V DC, with a permissible range from 5 mA to 0.6 A across 0 to 60 °C. The module occupies 1 slot from position 8 on the S7-1200 rail and measures 10 mm wide, 64 mm high, and 51 mm deep — a narrow footprint that fits into compact control cabinets.
Current derating and load handling
At 40 °C ambient, each output can deliver 1 A continuously; this derates to 0.8 A at 60 °C. The module includes electronic short-circuit protection with a typical response threshold between 0.7 A and 1.8 A. Switching speeds are 200 µs from 0 to 1 and 1.3 ms from 1 to 0. Maximum load switching frequency is 100 Hz for resistive loads, 2 Hz for inductive loads per IEC 60947-5-1 (DC-13/AC-15 at 0.3 A), and 1 Hz for lamp loads. The module limits inductive shutdown voltage to typically (L+) -48 V, protecting downstream contacts and the output stage from voltage spikes.
Isolation and diagnostics
Channel-to-backplane isolation uses an optocoupler, tested at 1500 V AC. Between different circuits, isolation is rated at 75 V DC / 60 V AC. There is no channel-to-channel isolation and no diagnostic function. A green status LED per output indicates the signal state. The module accepts a TB 16SC terminal block and supports shielded cable runs up to 1000 m, unshielded up to 600 m.