Product Description:

B & R Automation manufactures the X20BB27, an expansion module in the X20 Fieldbus Input Output Modules series. The unit serves as a fieldbus coupler that brings distributed sensors and actuators onto the machine CAN network while preserving compact rail space. By providing direct power routing and communication links, it reduces separate wiring runs between the control cabinet and remote I/O points in industrial automation cells.

The module draws 0.53 W from the backplane during logic activity, so the host power supply sees only a minor load increase. All connected peripherals receive a stabilized 24 VDC I/O supply that is routed through the board as GND and +24 VDC potentials. The module includes 1 CAN bus interface for cyclic process data, and a dedicated 1 RS232 interface is available for service diagnostics or legacy point-to-point devices. Communication lines are not galvanically isolated from the internal bus, so the bus, CAN, and RS232 sections share a common reference inside the assembly. The housing carries an IP20 protection rating, allowing installation in enclosed control cabinets. For line termination, an integrated 120 Ω CAN resistor is present and can be enabled or bypassed by a switch, which removes the need for external plug-in terminators.

The relay paths on the carrier can conduct up to 10 A, allowing the module to transfer substantial load currents without external relays. Mounting is supported in horizontal and vertical orientations, which gives more flexibility when rail space is limited in dense panels. When the assembly is used above 2000 m, the allowable ambient temperature drops by 0.5 °C/100 m, so altitude derating must be considered during layout. The CAN line ending resistor remains under user control through the switchable terminator feature, which allows termination changes after the panel is closed.