CMA137 ABB System 800xA Connection Modules

ABB CMA137 System 800xA Connection Module

Configured for signal routing and field termination in System 800xA platforms, the ABB CMA137 (CMA137 Connection Module) provides direct physical/electrical execution. It establishes reliable physical wiring paths between field instrumentation—including sensors, transmitters, and actuators—and central PLC or I/O processing hardware. The module accommodates direct 24 VDC system distribution across a compact enclosure designed to withstand electrical noise and harsh cabinet conditions.

Hardware Specifications

Backplane Bus Communication Velocity and Deterministic I/O Interfaces

The module optimizes data routing and signal continuity across system backplane interfaces without adding protocol conversion overhead. Through structured internal trace paths and terminal block interfaces, it maintains high-velocity signal transmission to primary process controllers while minimizing cross-talk and propagation delay. Built-in routing layers support high I/O density scaling, enabling clean panel wiring and reliable communication loop integration under demanding bus clock cycles.

Frequently Asked Questions

Q: How does the unit maintain signal integrity across long field wiring runs?

A: Internal conductive pathways and dedicated grounding points reduce stray capacitance and suppression interference, ensuring low signal loss between field transmitters and control modules.

Q: What power supply parameters are required for operation within an ABB DCS cabinet?

A: The module requires a standard 24 VDC supply rail, accommodating system distribution tolerances typical of ABB DCS cabinet setups.

Q: Can the connection module be serviced without disconnecting individual field instrument cables?

A: Depending on the terminal block configuration, field wiring disconnects cleanly at the module boundary, facilitating straightforward module replacement without unwiring field sensors or actuators.

Field Installation Guidelines

Mount the module securely on a standard DIN rail inside an IP54 or higher rated industrial panel to prevent exposure to dust and moisture. Maintain clear separation between high-voltage power lines and low-voltage signal cables to prevent electromagnetic interference.

Ensure all field instrument cables—including input lines from sensors and transmitters and output lines to actuators—are properly stripped and clamped into their respective terminal blocks. Fasten the ground wire directly to the central panel cabinet functional earth bar using a low-impedance conductor. Verify 24 VDC power supply polarity before applying power to the rack assembly.