Product Description:

The X20RT8401 module is a mixed-signal remote terminal from B&R Automation within the X20 Fieldbus Input Output Modules series. It links sensors, actuators, and incremental encoders to the system bus so that a central CPU can read process states and issue drive commands. By combining four analog lines, four digital inputs, and a high-speed encoder channel in one housing, the device reduces cabinet wiring and supports decentralized architectures commonly used in packaging, material handling, and CNC cell extensions.

Each analog channel presents an input impedance of 20 MΩ, protecting delicate transducers from loading effects, and both the inputs and the voltage-driven outputs share a span of ±10 V for direct connection to industrial signal standards. The internal converter samples incoming waveforms at up to 500 kHz, while the digital-to-analog stage refreshes commands in 2 µs, allowing tight PID loops. Despite these rates, the module draws only 0.01 W from the backplane for logic, and each digital input is limited to 1.3 mA of sink current through an 18.16 kΩ path. The quartet of digital points is debounced in hardware to ease PLC scanning.

The encoder interface counts quadrature edges with a 32-bit register, giving a single-turn range of over four billion positions and permitting zero-loss rollover during sustained motion. Edge capture is qualified up to 333 kHz, so shafts moving at high linear speed can still be resolved precisely, and the board can source up to 600 mA at 5 V to power the transducer. Internal I/O electronics dissipate 1.7 W, and the available mix of channels supports applications that need both sensing and actuation. The terminal can deliver a nominal 100 mA from its voltage outputs, sufficient for most proportional valves or signal relays without auxiliary drivers.