Product Description:

The X20DI2377 is a digital input slice produced by B & R Automation for the X20 Fieldbus Input Output Modules series. Designed for decentralized installations, it receives 24-volt sensor signals and forwards the resulting logic states to the fieldbus. This allows machine controllers to supervise limit switches, proximity sensors, or other binary devices within automated production cells.

At the electrical level, the module operates from a nominal system supply of 24 VDC, and its inputs comply with the EN 61131-2 Type 1 standard, which guarantees consistent switching points under load. It provides 2 digital inputs wired with a 3-wire arrangement and employs a sink input circuit so the external device sources current into the card. Each channel draws 10.5 mA in the high state and presents an internal impedance of 2.23 kΩ. Logic “1” is accepted above 15 VDC, while logic “0” is rejected below 5 VDC, yielding ample noise margin. Internal electronics dissipate only 0.15 W of bus power, a separate sensor feed supplies up to 0.5 A, and galvanic isolation of 500 Veff protects the controller. In addition to simple state detection, the module maintains two event counters that latch edge transitions for time-critical diagnostics.

For pulse-based measurements, each channel can accumulate counts at rates up to 50 kHz with a counter width of 16-bit, supporting flow meters or incremental encoders without overflowing too rapidly. These hardware counters run independently of the cyclic fieldbus scan, ensuring deterministic capture when scan times vary. An IP20 housing makes the card touch-safe yet suitable only for protected cabinets. By combining dedicated counting logic with precise thresholds and integrated isolation, the X20DI2377 fits into distributed I/O nodes that must relay both discrete states and high-speed pulse information to the central PLC.