Product Description

Overview

The ABB CMA51 is a high-performance Man-Machine Communication (MMC) module designed for the Advant Controller 400 (AC 400) series. This dual-channel serial communication module provides robust, real-time data exchange between the controller and external devices such as printers, terminals, and supervisory systems. By offloading serial processing tasks from the main CPU, the CMA51 ensures system stability and uninterrupted operation in demanding industrial environments.

Technical Features

Dual Independent Channels
The module supports two fully configurable serial channels. Each channel can operate independently for different tasks, enabling simultaneous communication with multiple devices or protocols.

Protocol Compatibility

• Standard ASCII for printer and terminal connections

• Modbus RTU (Master/Slave) for integration with PLCs, drives, and sensors

• EXCOM for external computer or supervisory system communication

High-Speed Data Handling

• Transmission rates range from 300 bps up to 19,200 bps

• Internal buffering prevents data loss during peak traffic, ensuring reliable performance

Physical Interfaces

• Supports RS-232C, RS-485, and RS-422 interfaces via termination units

• Galvanic isolation protects the controller from electrical interference and surges

System Integration

• Hot-swappable design allows module replacement without powering down the entire rack

• Built-in diagnostics with LED indicators for RUN, FAULT, and TX/RX status

• Error reporting integrated with Advant Station for streamlined troubleshooting

Technical Specifications

Applications

The CMA51 is widely used for logging, local monitoring, and legacy system integration in manufacturing plants, process automation, and supervisory control systems. Its dual-channel design allows seamless interfacing with multiple devices without compromising performance.

FAQ

Q: Can the CMA51 handle both Modbus RTU and ASCII communication simultaneously?
A: Yes, the dual-channel architecture allows one channel to run Modbus RTU while the other handles ASCII or EXCOM protocols independently.

Q: Is the module hot-swappable?
A: Yes, it can be replaced without powering down the AC 400 rack, provided the baseplate supports hot-swap operation.

Q: What is the maximum baud rate supported?
A: The module supports up to 19,200 bps, depending on the interface type and cable length.