Product Description:

B & R Automation’s X20CM8281 is a combined analog, digital, and counter slice in the X20 Fieldbus Input Output Modules series. Mounted on an X20 backplane, the unit gives a controller access to mixed-signal acquisition and generation from one module position. A CPU board can read process values, drive proportional actuators, monitor switching states, and process pulse-based feedback without using separate cards. Communication takes place over the system bus, so operating data is exchanged within a compact I/O layout. This arrangement can also reduce panel space and field wiring on machines that need several signal types in one station.

The analog circuitry accepts ±10 V, 0 to 20 mA, and 4 to 20 mA signals, so the channel can interface with either voltage or current transmitters. Conversion on the single analog input and output is performed at 12-bit resolution, which provides 4,096 steps for closed-loop regulation and signal scaling. One analog input and one analog output are combined in the same slice, which suits feedback and setpoint tasks in compact control assemblies. For high-speed feedback, the module includes counter channels that can operate as an Event counter for pulse accumulation from encoders, flow pickups, or similar devices. It also provides four digital inputs that use a 24 VDC sink interface for proximity switches, limit devices, and interlock signals.

When period-based evaluation is needed, the counters can be switched to gate measurement mode. The module also provides 24 VDC, 0.5 A sourcing outputs as two digital outputs for solenoid valves, relays, or status lamps. These outputs are suitable for device signaling while the analog section handles process-value transmission at the same time. Its analog output can retransmit scaled process values to external drives or indicators without extra signal conditioning. The same module position can therefore support pulse monitoring, discrete control, and analog signal handling in parallel during machine operation.