ABB 3BSE093350R1 – Low-Power AC 800M CPU with Native Modbus TCP Support

The ABB PM858-C 3BSE093350R1 is a compact, cost-efficient central processing unit (CPU) from ABB’s AC 800M programmable automation controller family, designed for small to medium-scale industrial applications. As a streamlined variant of the PM85x series, it delivers full IEC 61131-3 programming support and native communication capabilities in a space-saving form factor.
With integrated Ethernet and RS-485 ports, 8 MB of program memory, and compatibility with the entire AC 800M I/O ecosystem, the PM858-C offers a powerful yet economical solution for panel-mounted control, remote skids, and distributed automation tasks.

Application Scenarios

At a municipal wastewater treatment plant in Sweden, engineers needed a reliable, low-maintenance controller for 12 pump station skids spread across a 50-km radius. Legacy PLCs suffered from communication dropouts and limited memory for future expansion. By deploying the ABB PM858-C 3BSE093350R1 at each site—with its built-in Ethernet port connecting directly to the SCADA system via cellular routers—the utility achieved 99.95% remote uptime over two years. The PM858-C’s compact size fit neatly into existing enclosures, while its 8 MB memory accommodated added logic for predictive pump health monitoring. This deployment turned isolated assets into intelligent, connected nodes—proving that high reliability doesn’t require high cost.

Technical Principles and Innovative Values

Innovation Point 1: The ABB PM858-C eliminates battery dependency through fully non-volatile flash memory—ensuring program retention for decades without maintenance, unlike older PLCs requiring periodic battery replacement.

Innovation Point 2: Native dual-protocol support (Modbus TCP over Ethernet + Modbus RTU over RS-485) enables direct integration with VFDs, meters, and legacy devices—reducing the need for external gateways and lowering system complexity.

Innovation Point 3: Despite its compact size, the PM858-C runs the same Control Builder M engineering environment as high-end CPUs like the PM864A or PM783F, enabling code reuse and standardized programming across plant-wide systems.

Innovation Point 4: Low power consumption (<5 W) and passive cooling allow installation in sealed or unventilated enclosures—ideal for outdoor pump stations, food processing washdown areas, or hazardous locations with thermal constraints.

Application Cases and Industry Value

In a North American bottled water facility, the ABB PM858-C 3BSE093350R1 replaced aging relay-based controls on 8 filling and capping lines. Each PM858-C managed motor sequencing, bottle-count tracking, and reject actuation—all while communicating production data via Ethernet to a central MES. The result: 30% faster line changeovers, real-time OEE reporting, and zero unplanned downtime due to controller failure over 18 months. Maintenance staff appreciated the intuitive diagnostics via ABB’s Automation Builder software.

Similarly, a Chilean mining operation used the PM858-C to automate slurry transfer skids in remote desert camps. With ambient temperatures exceeding 50°C, the CPU’s wide operating range and solid-state design outperformed competitors that required active cooling. “It just works,” said the site engineer—“even when sand gets in the cabinet.”