ABB P-HC-BRC-40000000 Harmony Bridge Controller

The ABB P-HC-BRC-40000000 is a bridge controller module for the ABB Harmony series programmable logic controllers. It serves as a communication gateway between Harmony I/O racks and higher-level control networks such as Modbus RTU, Modbus TCP, or ABB’s proprietary SattBus. The module replaces the earlier Harmony CPU in bridge applications, providing protocol conversion and data concentration.

Processor and Memory

The module features a 16-bit microcontroller (68HC11) at 16 MHz with 128 KB of firmware flash, 32 KB of RAM for user data, and 2 KB of EEPROM for configuration retention. The real-time clock with battery backup (lithium coin cell) maintains timestamps for event logging. The maximum I/O points addressed: 256 digital or 64 analog.

Communication Ports

Two RS-232/RS-485 serial ports (software selectable) support Modbus RTU master or slave (baud rates up to 115.2 kbps). One optional Ethernet port (via a separate expansion) allows Modbus TCP. The module also has a dedicated programming port (RS-232, 19.2 kbps) for configuration with ABB Harmony Builder software. On the backplane side, it communicates with Harmony I/O modules via a 16-bit parallel bus.

I/O Mapping and Data Handling

The bridge controller scans the I/O racks (up to 8 racks, each with 16 modules) cyclically with a scan time of 5 ms per rack. It then maps the I/O data into a Modbus register table (holding registers and discrete inputs). Users can define up to 500 Modbus registers for data exchange. The module also supports email alarms on critical events (requires Ethernet option).

Electrical and Environmental

Power supply: 24 V DC (-15% / +20%), consumption 2 W. Dimensions: 120 mm x 90 mm x 60 mm. Weight: 0.3 kg. Operating temperature: 0°C to 60°C. Storage: -40°C to 85°C. Protection: IP20. The controller is DIN rail mounted and includes a removable terminal block for power and serial ports. Status LEDs show power, run, error, and port activity.

Typical Application

The P-HC-BRC-40000000 is used to modernize legacy Harmony systems by integrating them with new SCADA or PLC networks without rewriting ladder logic. It acts as a transparent bridge: the original Harmony CPU (if present) can be placed in stop mode while the bridge reads inputs and writes outputs. For systems without a CPU, the bridge provides full control capability via remote Modbus master.