Mixed analog I/O for legacy S7-300 racks
The 6ES7334-0KE00-0AB0 is a Siemens SM 334 analog I/O module for the S7-300 family, combining 4 analog inputs and 2 analog outputs in a single 40 mm-wide unit. It accepts voltage inputs (0 to 10 V, 0 to +10 V), resistance measurements (0 to 10000 ohms), and Pt100 resistance thermometers — but only for the climatic range, not the full industrial Pt100 curve. The module draws 60 mA from the 5 V DC backplane bus and 24 V DC from the field supply, with reverse polarity protection on the field side.
Integration and wiring constraints
The module requires a 20-pin front connector (sold separately) and fits a standard S7-300 DIN-rail slot. Dimensions are 125 mm high, 40 mm wide, and 117 mm deep — the 40 mm width consumes one slot in the rack. Shielded cable runs up to 100 m are supported. The input resistance on the 0 to 10 V range is 100 kΩ; the voltage outputs require a minimum load of 2.5 kΩ. Conversion time per channel is 500 µs, with a maximum cycle time of 85 ms across all channels. Integration time is parameterizable at 16.67 ms or 20 ms (50/60 Hz rejection). Isolation is tested at 500 V DC between channels and the backplane bus, but there is no channel-to-channel isolation.