Description
Detailed Parameter Table
| Parameter Name | Parameter Value |
| Product Model | CMA198 |
| Manufacturer | ABB |
| Product Category | Analog Output Module (Advant OCS Series) |
| Output Type | 4-20 mA (active) |
| Channel Count | 8 channels |
| Resolution | 12-bit |
| Accuracy | ±0.15% of span |
| Load Capacity | 0-750 Ω per channel |
| Update Rate | 10 ms per channel |
| Connection Interface | 37-pin D-sub connector |
| Power Consumption | 2.5 W (max) |
| Operating Temperature | 0°C to +60°C |
| Certifications | CE, UL 508, EN 61326 (EMC) |
ABB CMA198
Product Introduction
The ABB CMA198 is a legacy 8-channel analog output module for ABB’s Advant OCS 200/400 Series, delivering precision 4-20mA control signals to field actuators. Designed for process control applications, this module interfaces with Master Piece 200/200HC controllers via the Advant Fieldbus 100 (AF100) network, enabling valve positioning, VFD speed control, and analog setpoint transmission. As a critical component of distributed control systems from the 1990s, the CMA198 maintains operational continuity in aging installations with its robust construction and deterministic performance.
Featuring individual channel short-circuit protection and automatic load compensation, the module ensures stable signal integrity even in electrically noisy environments. Its plug-in design allows hot-replacement in redundant configurations, minimizing downtime during maintenance. Though superseded by modern S800 I/O systems, the CMA198 remains vital for retrofitting and lifecycle extension in power, pulp/paper, and water treatment facilities.
Core Advantages and Technical Highlights
Precision Control:
±0.15% output accuracy with 12-bit resolution ensures precise actuator positioning. Active current sourcing (24V loop supply) drives loads up to 750Ω without external power.
Robust Field Connectivity:
Integrated transient voltage suppressors (TVS) protect against 1kV surges. Galvanic isolation (250VAC) between channels prevents ground loop interference.
Legacy System Integration:
Direct compatibility with AF100 fieldbus (1.5 Mbps) enables real-time data exchange with AC 410/450 controllers. Backward-compatible with CMA120/CMA130 mounting hardware.
Diagnostic Capabilities:
Per-channel LED status indicators (green=active, red=fault). Automatic detection of open-wire and overload conditions (>30mA). Faults reported via Operator Station 410 alarm logs.
Typical Application Scenarios
The ABB CMA198 operates in critical legacy systems including:
Power Generation: Governing valve control in steam turbines
Pulp & Paper Mills: Consistency valve positioning in stock preparation
Chemical Processing: Reactor feed flow control via control valves
Water Distribution: Pump speed modulation in booster stations
HVAC Systems: Damper actuator control in air handling units
ABB CMA198
Related Model Recommendations
CMAV98: Voltage output version (0-10VDC)
CMA124: 4-channel high-density variant
IMDSI23: Digital input module for complementary monitoring
S800 AO810: Modern analog output (migration path with SAI01 adapter)
CI522: AF100 to OPC gateway for legacy integration
Installation, Commissioning and Maintenance Instructions
Installation Preparation:
Verify rack slot compatibility (Advant OCS Baseplate B01). Ensure backplane voltage 5V±5%. Use twisted-pair shielded cables (Belden 8760) with drain grounded at control cabinet. Maintain 10cm separation from AC power lines.
Maintenance Protocol:
Biannual calibration using ABB Calibration Toolkit. Quarterly:
Inspect D-sub contacts for oxidation
Verify output current with precision shunt (0.1%)
Check load impedance (<750Ω)
Replace electrolytic capacitors every 8 years. Always discharge modules before handling.
Service and Guarantee Commitment
ABB provides extended lifecycle support for the CMA198:
10-Year Spare Commitment: Guaranteed availability until 2030
Legacy Technical Hotline: Migration advisory services
Refurbishment Program: Component-level repair with 12-month warranty
Firmware Recovery: Archived versions via ABB Support Portal
Note: New units discontinued; refurbished units carry 6-month warranty. Calibration services available at ABB service centers.
