The Siemens 6ES7123-1GB10-0AB0 is a 2-channel analog input module for the SIMATIC S7-1200 controller family, accepting 4 to 20 mA or ±20 mA current signals with a 12-bit (4 to 20 mA) or 13-bit (±20 mA) resolution including overrange. It occupies one slot in the CPU rack and draws its 24 V DC supply from the backplane, with a typical power loss of 0.6 W. The integrating measurement principle gives a basic conversion time of 55 to 65 ms, with a parameterizable integration time of 50 or 60 ms — matching the line frequency to reject 50/60 Hz noise. That makes this module a fit for process signals where noise rejection matters more than raw speed.
At 10 mm wide, 64 mm tall, and 51 mm deep, this module slides into a standard S7-1200 rack without crowding adjacent I/O slices. The usable terminal block is a TB 16SC, and the input resistance is 50 Ω for both current ranges. Shielded cable runs up to 200 m are supported. Reverse polarity protection is built in, and isolation between channels and the backplane bus is via optocoupler, tested at 1,500 V AC. There is no channel-to-channel isolation, so common-mode voltage between the inputs and MANA (UCM) must stay within 2 V DC / 2 Vpp AC.