ABB AC 800M PM851 3BSE066485R1 Module CompactFlash

Product Description

Core Processing Unit for AC 800M Control Systems

The PM851 (Model: PM851) is a high-reliability central processing unit designed for the ABB AC 800M controller family. As an entry-to-mid-range processor within the System 800xA architecture, the PM851 (Article Number: 3BSE066485R1 / PM851AK01) provides the computational power required for real-time process control, logic execution, and communication management. The module features a modular hardware design, incorporating a microprocessor, RAM for application logic, a real-time clock (RTC), and a CompactFlash interface for non-volatile storage of application programs and system cold starts.

Detailed Technical Specifications

The PM851 (3BSE066485R1) is engineered for deterministic performance in industrial automation and safety-critical monitoring environments.

• Manufacturer: ABB

• Model Designation: PM851

• Article Number: 3BSE066485R1 (Kit: PM851AK01)

• Product Type: CPU Module

• Clock Frequency: 24 MHz

• Total Memory: 12 MB

• Application RAM Available: 6.253 MB (Reference: 800xA 5.1 FP4)

• Flash Memory Support: Integrated CompactFlash slot for offline storage

• Ethernet Communication: 2 × RJ45 ports (CN1 and CN2; Note: CN1 is the primary usable port for control network)

• Serial Interfaces: 2 × RJ45 ports (COM3: RS-232C, COM4: Isolated)

• System Redundancy: Not supported (Single CPU configuration)

• Mounting Method: Standard DIN rail with slide-and-lock mechanism

• Physical Interface: INIT push button and integrated LED diagnostic indicators

• Certifications: CE, TÜV, and IEC 61508 compliance

• System Platform: Compatible with ABB 800xA and Compact Control Builder

Communication and Hardware Integration

The PM851 (3BSE066485R1) excels in localized control tasks where connectivity to operator stations and engineering tools is paramount. The dual serial ports allow for direct interfacing with peripheral devices via RS-232C or isolated communication links. For network integration, the onboard Ethernet port (CN1) facilitates seamless connection to the 800xA Control Network. Its hardware architecture is built to ensure high electromagnetic compatibility (EMC), minimizing the risk of signal corruption in high-voltage switching environments.

Core Application Scenarios

• Small to Mid-Scale Process Control: Ideal for standalone production units and OEM machinery control.

• Safety Instrumented Systems (SIS): Utilized in non-redundant safety monitoring layers following IEC 61508 standards.

• Distributed I/O Management: Serving as the head-end processor for S800 I/O clusters via ModuleBus.

• Utility Control: Managing HVAC, water treatment, and auxiliary power systems in industrial facilities.