The Siemens 6ES7131-6BF00-0CA0 is an ET 200SP digital input module with 8 channels, each accepting 24 V DC signals. It supports both standard DI and MSI (Module-Specific Input) operation, meaning the same slot can handle standard sensors or, with a parameter change, read module-specific status data without extra wiring. Rated supply voltage is 24 V DC; typical power loss runs 1.5 W when all eight inputs are supplied via the encoder supply. The module draws that from the backplane bus, so budget the ET 200SP station's total power accordingly.
Input signal thresholds: a logic '0' spans -30 to +5 V, and a logic '1' spans +11 to +30 V. That 6 V deadband between 5 V and 11 V rejects noise from long cable runs — important when you're pulling 600 m unshielded or 1000 m shielded, the maximums the module supports. Input filtering is parameterizable: the minimum '0' to '1' transition time is 0.05 ms, maximum 20 ms. For fast counting or edge evaluation (rising, falling, or both), set the filter low. For noisy environments, lengthen it to avoid false triggers. Wire-break diagnostics is configurable per channel, with an optional 25 kΩ to 45 kΩ pull-up resistor for simple encoder contacts. That resistor lets the module distinguish an open wire from a sensor that's just off — a real time-saver during fault-finding on a conveyor line. Jitter is specified at 8 µs maximum, and isochronous mode is supported. That means the module can participate in equidistant cycle-synchronous operation, critical for motion-control applications where input timing must align with the drive cycle.
Mounting and BaseUnit compatibility
Width is 15 mm, depth 58 mm, height 73 mm. At 28 g it's light, but the 15 mm pitch matters when you're packing I/O into a crowded cabinet — each module takes one slot on the DIN rail, and the ET 200SP bus connector passes through.