ABB PM864AK01 3BSE018161R1 Processor Unit

The PM864AK01 is a core component of ABB's AC 800M controller hardware platform, representing a high-performance, highly reliable processor unit. It consists of the PM864A Processor Unit combined with the TP830 Baseplate, designed specifically for complex control applications in industrial automation. As a member of the AC 800M controller family, the PM864AK01 integrates powerful processing capabilities, flexible communication expansion, and a rugged industrial-grade design, meeting diverse requirements ranging from simple logic control to complex Distributed Control Systems (DCS) and High Integrity systems.

The AC 800M platform is a modular hardware system where users can configure the processor unit with various communication interface modules, I/O units, and power supply modules according to specific application needs. Within this ecosystem, the PM864AK01 acts as the "brain," responsible for executing control logic, processing data, managing communications, and coordinating the operation of the entire control system. It is particularly well-suited for applications demanding high processing performance, system availability, and communication diversity, such as process industries, manufacturing, energy management, and infrastructure control.

The PM864AK01 not only supports operation as a standalone controller but also integrates seamlessly into control networks comprising multiple controllers, operator stations, and servers, enabling large-scale, distributed automation solutions. Its design fully considers the harsh demands of industrial environments, featuring excellent Electromagnetic Compatibility (EMC), a wide operating temperature range, and reliable mechanical construction, ensuring long-term stable operation in critical industrial settings.

II. Key Features and Advantages

1. Outstanding Processing Performance:

• Core Processor: Equipped with a 96 MHz MPC862 microprocessor, delivering robust computing power.

• Memory Configuration: Features 32 MB of SDRAM, ensuring smooth operation of complex application programs and multi-tasking.

• Compared to Predecessors: Its theoretical peak performance is up to twice that of the PM860 processor. The actual sustained performance improvement, depending on the application, ranges from 10% to 50%, significantly enhancing system responsiveness and data handling capability.

2. Flexible Communication and Expansion Capabilities:

• Rich On-board Communication Ports: Provides four standard communication ports: two 10BaseT Ethernet ports (CN1, CN2), one RS-232C serial port with modem support (COM3), and one RS-232C service port for tools (COM4), facilitating network and peripheral connections.

• Powerful Expansion Bus: Through the CEX-Bus (Communication Expansion Bus), numerous communication interface modules can be connected, such as PROFIBUS DP, FOUNDATION Fieldbus H1/HSE, Modbus TCP, PROFINET IO, EtherNet/IP, etc., enabling easy interconnection with various fieldbuses and intelligent devices.

• Local I/O Connection: Built-in electrical ModuleBus allows direct connection of one local cluster containing up to 12 S800 I/O modules for fast and reliable local signal processing.

3. High Availability and Redundancy Support:

• Processor Redundancy: The PM864A supports pairing with another PM86x or PM891 to form a redundant pair, enabling bumpless primary/backup switchover. In case of a primary processor failure, the backup can take over control within 10 milliseconds, with process outputs frozen, maximizing system uptime.

• Fault Tolerance Mechanism: Employs advanced synchronization technology based on execution units and rollback points, ensuring the backup unit's state is consistently aligned with the primary unit.

• Online Maintenance: Supports replacement of a faulty processor unit while the system is running (online replacement), greatly reducing unplanned downtime.

4. High Integrity System Support:

• The PM864A can serve as the foundation for an AC 800M High Integrity (HI) controller. Combined with the SM810/SM811 Safety Monitoring Unit and SIL-certified S800 I/O HI units, and running the High Integrity version of the controller software, it can build a safety system certified to IEC 61508 SIL2 by TÜV.

• The PM865 (an enhanced version of PM864) offers further advancements in this area, integrating features like dual overvoltage protection, enhanced oscillator supervision, and online self-tests.

5. Reliable Data Storage and Backup:

• Storage Media: Features a Compact Flash card interface for storing application programs and cold retain data, facilitating program loading, backup, and recovery.

• Battery Backup: Offers both internal and external battery (SB821, SB822) backup solutions to maintain RAM memory and Real-Time Clock (RTC) data during external power loss. The PM864A's internal battery backup time is significantly improved, with a minimum of 235 hours.

6. Rugged Industrial Design and Certifications:

• Mounting: Uses standard 35mm DIN rail mounting, compact and easy to install/maintain.

• Protection Rating: IP20, providing basic protection against dust and finger contact.

• Extensive Certifications: Complies with EU EMC Directive (2004/108/EC) and Low Voltage Directive (2006/95/EC), meets international standards such as UL 508, UL 60079-15 (for hazardous locations), and offers optional TÜV certification, suitable for various industrial environments.

III. System Architecture and Composition

The physical architecture of the PM864AK01 clearly reflects its modular design philosophy:

1. Processor Unit (PM864A):

• This is the core functional module, containing the CPU board, power supply board, and front panel.

• CPU Board: Integrates the MPC862 microprocessor, SDRAM, communication controllers, real-time clock, LED indicators, INIT pushbutton, and CF card interface.

• Power Supply Board: Converts the input 24V DC to isolated +5V and +3.3V supplies for the CPU and I/O units. It also contains opto-isolated RS-232C drivers/receivers for the service port and the internal battery holder.

• Front Panel: Provides status display and basic operation interface.

2. Baseplate (TP830):

• This is the connection hub of the system, permanently mounted on the DIN rail.

• Termination Board: Centralizes most external connection terminals, including screw terminals for power and redundant power supervision, RJ45 connectors for the control network and service port, the electrical ModuleBus plug, and the CEX-Bus connector.

• Grounding: Grounded to the DIN rail via metal housing components, enhancing noise immunity.

• Power Distribution: The 24V DC power connected to the TP830 supplies all units on the CEX-Bus and the electrical ModuleBus.

Typical System Configuration Example:
An AC 800M controller system centered around the PM864AK01 may include:

• Central Unit: PM864AK01 processor unit.

• Communication Expansion: Via the left-side CEX-Bus, connect a CI854A PROFIBUS DP interface module to link remote S800 I/O stations (e.g., via CI801 FCI units), expandable up to 768 I/O modules. Simultaneously, a CI860 module can be added to connect to a FOUNDATION Fieldbus HSE network.

• Local I/O: Via the right-side electrical ModuleBus, connect one S800 I/O cluster with up to 12 modules.

• Remote Optical I/O: Via the on-board optical ModuleBus port, connect TB820 optical modems to expand up to 6 additional remote optical ModuleBus clusters (max 12 modules each), supporting a total of up to 84 remote optical I/O modules.

• Power System: Powered by SD83x series power supply modules, optionally configured with SS823/SS832 voting units for power supply redundancy, and connected to SB821 or SB822 external batteries for extended memory backup.

In a redundant configuration, two PM864A processors are connected via the RCU Link cable, share the same CEX-Bus, and connect to the optical ModuleBus of each S800 I/O cluster via two independent TB840 cluster modems, ensuring I/O communication continuity if either CPU fails.

IV. Application Fields

Thanks to its high performance, reliability, and excellent scalability, the PM864AK01 is suitable for numerous demanding industrial automation fields:

1. Process Industries: Distributed Control Systems (DCS) in oil & gas, petrochemical, refining, pharmaceuticals, water treatment, etc., for continuous process control, safety interlocks, and batch processing.

2. Power & Energy: Auxiliary control systems in power plants (thermal, hydro, renewable), grid monitoring, Energy Management Systems (EMS), and substation automation.

3. Manufacturing: Production line control, machine control, and MES interfaces in discrete and batch manufacturing such as automotive, food & beverage, and semiconductor production.

4. Infrastructure: Building automation, metro/railway signaling and control, tunnel ventilation/lighting control, port logistics systems.

5. High Integrity Safety Systems: As part of safety-related control systems requiring SIL2 Safety Integrity Level, e.g., boiler protection systems, Emergency Shutdown Systems (ESD), Fire & Gas detection systems (F&G) (requires combination with SM810/SM811 and HI software).