Product Description:

B & R Automation produced the 3EX450.77-1 module for its System 2005 Controllers series. Installed on the system backplane, this unit operates as a fieldbus controller that bridges the internal processor to external industrial networks. By sequencing telegrams, buffering process variables, and monitoring network status, it lets a PLC coordinate sensors, valves, and drives without dedicating CPU time to physical-layer signaling. The module therefore expands node counts and keeps cycle times predictable in distributed automation cells.

The communication layer is configured for the DeviceNet Master role, allowing it to supervise up to 63 slaves while exchanging up to 3.5 kB of input data and 3.5 kB of output data per scan. The first local service channel, identified as If1, uses a 9-pin Male DSUB connector and the RS232 protocol for diagnostics or firmware loading. That port sustains a peak transfer rate of 9.6 kbit/s, adequate for parameterization tasks. Power is drawn from two backplane supplies: the 24 V rail contributes 1.1 W, and the 5 V rail provides 4.4 W, so heat dissipation on the board remains low. An SJA 1000 CAN controller manages arbitration timing and error handling to maintain bus integrity during high-priority traffic.

If2 is the high-speed field interface. It terminates on a 5-pin Phoenix Combicon block and uses the CAN physical layer to move process messages. Galvanic isolation is provided between the bus and logic domains, and the link can sustain a maximum throughput of 500 kbit/s for time-critical transactions. The housing carries an IP20 protection rating, so the card is intended for enclosed control cabinets with controlled airflow. Overall consumption is limited to 5.5 W, enabling dense rack layouts without overloading the power supply. By concentrating high-bandwidth messaging on If2 while leaving configuration on If1, the module separates real-time data from maintenance traffic and maintains predictable latency across the controlled network.