ABB AC 800M System Modules: Types, Models and Main Functions

The ABB AC 800M is a modular, rail-mounted programmable automation controller (PAC) family, serving as the core of the ABB Ability™ System 800xA automation platform. Its hardware structure is composed of four main types of modules: CPU modules, communication modules, power supply modules, and auxiliary accessories. Each type of module has multiple specific models, which are designed to meet different industrial control needs with distinct functions. The detailed introduction of each module, its models and main functions is as follows:

CPU Modules

CPU modules are the core computing unit of the AC 800M system, responsible for running control programs, processing industrial data, and coordinating the operation of other modules. They cover a variety of models, ranging from cost-effective medium-performance units to high-performance units supporting full redundancy, with different processing capabilities and memory configurations to adapt to different scale control tasks.

• PM851A / PM851AK01: A cost-effective non-redundant CPU module with a processing speed of 0.46 ms for 1000 boolean operations. It has 12 MB of memory (updated from 800xA 5.1 FP4) and is suitable for small-scale, non-critical control scenarios that do not require redundancy support.
• PM856A / PM856AK01: A non-redundant CPU module with the same processing speed (0.46 ms for 1000 boolean operations) as PM851A, but with an increased memory capacity of 16 MB (updated from 800xA 5.1 FP4). It is suitable for medium-scale control tasks with higher memory requirements.
• PM857K01 / PM857K02: High-integrity (HI) CPU modules certified by IEC 61508-SIL 3, with a processing speed of 0.17 ms for 1000 boolean operations and 32 MB of memory. PM857K01 is non-redundant, while PM857K02 supports full redundancy, making them suitable for safety-critical applications that require SIL 1-3 configurations.
• PM858K01 / PM858K02: Non-HI CPU modules with a processing speed of 0.36 ms for 1000 boolean operations and 16 MB of memory. PM858K01 is non-redundant, and PM858K02 supports redundancy, suitable for medium to large-scale control tasks that require balanced performance and reliability.
• PM860A / PM860AK01: A non-redundant CPU module with a processing speed of 0.23 ms for 1000 boolean operations and 16 MB of memory (updated from 800xA 5.1 FP4), offering better processing performance than PM851A and PM856A.
• PM862K01 / PM862K02: Non-HI CPU modules with a processing speed of 0.18 ms for 1000 boolean operations and 32 MB of memory. PM862K01 is non-redundant, and PM862K02 supports redundancy, suitable for large-scale control tasks with high processing efficiency requirements.
• PM863K01 / PM863K02: HI CPU modules certified by IEC 61508-SIL 3, with the same processing speed (0.17 ms) and memory (32 MB) as PM857. PM863K01 is non-redundant, while PM863K02 supports redundancy, designed for safety-critical applications that require high reliability and SIL compliance.
• PM866A / PM866AK01 / PM866AK02: High-performance non-HI CPU modules with a processing speed of 0.09 ms for 1000 boolean operations and 64 MB of memory. PM866AK01 is non-redundant, and PM866AK02 supports redundancy, suitable for large-scale, complex control tasks that require high computing power.
• PM867K01 / PM867K02: High-performance HI CPU modules certified by IEC 61508-SIL 3, with a processing speed of 0.09 ms for 1000 boolean operations and 64 MB of memory. PM867K01 is non-redundant, and PM867K02 supports redundancy, ideal for safety-critical applications with high computing requirements.
• PM891K01 / PM891K02: The highest-performance non-HI CPU modules, with a processing speed of 0.043 ms for 1000 boolean operations and 256 MB of memory. PM891K01 is non-redundant, and PM891K02 supports redundancy, suitable for ultra-large-scale and complex control scenarios that require extremely high processing efficiency. It adopts an MPC8270 microprocessor with a running speed of 450 MHz, and its performance is about 3 times that of PM864.

ABB AC 800M System

Communication Modules

Communication modules are responsible for realizing data exchange between the AC 800M controller and field devices, third-party systems, and other components in the system. They support a variety of industrial communication protocols, enabling seamless integration and interoperability in complex industrial environments. All communication modules support hot-swappable function for easy maintenance.

• CI853 (Article No.: 3BSE018103R1): Supports COMLI and MODBUS RTU protocols, with 2 channels and a transmission speed of 75-19200 b/s. It supports line redundancy and module redundancy, can be used with HI controllers, and is mainly used for serial communication and MODBUS-based data exchange with field devices.
• CI854B (Article No.: 3BSE069449R1): Supports PROFIBUS DP-V1 protocol, can work as master or slave, with a transmission speed of 9.6-12000 kbit/s. It does not support line redundancy or module redundancy, can be used with HI controllers, and is used for communication with S800 I/O modules and other PROFIBUS DP-compatible devices.
• CI855 (Article No.: 3BSE018106R1): Supports ABB’s MasterBus 300 protocol, works as a master, with a transmission speed of 10 mbit/s and 200 datasets/s. It is used for data exchange with Advant Controller 450 and Masterpiece 200, and can realize interlocks between controllers.
• CI856 (Article No.: 3BSE026055R1): Supports ABB’s S100 I/O protocol, works as a master, and each module can support up to 5 S100 I/O racks. It is mainly used for communication with Advant Master S100 I/O racks.
• CI857 (Article No.: 3BSE018144R1): Supports ABB’s INSUM protocol, works as a master, with a transmission speed of 10 mbit/s. It can be used with HI controllers and is used for specific communication scenarios based on INSUM protocol.
• CI858 (Article No.: 3BSE018135R1): Supports ABB’s DriveBus protocol, works as a master, with a transmission speed of 8 mbit/s. It can be used with HI controllers and is mainly used for communication with ABB drives.
• CI860 (Article No.: 3BSE032444R1): Supports FOUNDATION Fieldbus HSE protocol, can work as master or slave, with a transmission speed of 10/100 mbit/s. It supports module redundancy and is used for communication with FOUNDATION Fieldbus HSE-compatible field devices.
• CI862 Classic (Article No.: 3BUA000037R1): Supports ABB’s Trio/Genius I/O protocol, works as a master, and its life cycle status is classic. It is used for communication with Trio/Genius I/O devices.
• CI869: Supports ABB’s Advant Fieldbus 100 protocol, used for data exchange with Advant Controller 450. If the Advant Controller 450 already has Advant Fieldbus 100, it can be used to realize interlocks between controllers.
• CI871: Supports PROFINET protocol, used for communication with S800 I/O modules, and requires replacing the existing Advant Fieldbus 100 with PROFINET.
• TB840: Used for Module Bus communication with S800 I/O modules, and requires replacing the existing Advant Fieldbus 100 with Module Bus.

Power Supply Modules

Power supply modules convert the mains voltage into stable 24V DC power to provide reliable power for the normal operation of all modules in the AC 800M system. They support non-redundant and redundant configurations, and redundant configurations require matching diode voting units. All power supply modules comply with RoHS and WEEE standards, with over-current and over-voltage protection functions.

• SD822Z (Article No.: 3BSC610054R1): A space-saving power supply module with a rated output current of 5A, rated output power of 120W, and rated output voltage of 24V DC. It is G3 compliant and suitable for small-scale systems with low power requirements.
• SD831 (Article No.: 3BSC610064R1): A switch-mode power supply module with a rated output current of 3A, rated output power of 72W, and rated output voltage of 24V DC. It supports both AC (100-240V) and DC (110-300V) input, with a wide input voltage range, and no need to install a mains filter.
• SD832 (Article No.: 3BSC610065R1): A switch-mode power supply module with a rated output current of 5A, rated output power of 120W, and rated output voltage of 24V DC. It supports AC input (100-120V, 200-240V, auto-select) and has a soft start feature to avoid tripping fuses or earth-fault circuit breakers during power-on.
• SD833 (Article No.: 3BSC610066R1): A switch-mode power supply module with a rated output current of 10A, rated output power of 240W, and rated output voltage of 24V DC. It supports AC input (100-120V, 200-240V, auto-select) and is suitable for medium-scale systems with higher power requirements.
• SD834 (Article No.: 3BSC610067R1): A high-power switch-mode power supply module with a rated output current of 20A, rated output power of 480W, and rated output voltage of 24V DC. It supports AC (100-240V) and DC (110-150V) input, can be connected in parallel to increase output power, and is equipped with a floating DC-OK relay contact.

ABB AC 800M System

Auxiliary Accessories

Auxiliary accessories are used to enhance the stability, maintainability and expandability of the AC 800M system, including voting units, battery backup modules, bus interconnection units, and flash memory cards, etc.

• SS823 / SS832: Diode voting units, which are required for redundant configurations of power supply modules. They ensure the stable switching of redundant power supplies and improve the reliability of the power supply system.
• SB821 / SB822: Battery backup modules. SB822 is a rechargeable lithium battery, used to provide backup power for memory and real-time clock when the main power is cut off, preventing data loss. PM891 only supports external battery backup (SB822).
• BC810K02 / BC820K02: CEX-Bus interconnection units. BC810K02 supports redundancy and hot swap, while BC820K02 supports hot swap. They are used to divide the CEX-Bus into independent segments, improve system availability, and support redundant communication interfaces.
• SM810 / SM811 / SM812: Intelligent monitoring modules for high-integrity controllers. SM811 can form a 1oo2 structure with PM865, and SM812 can form a 1oo2 structure with PM867, both supporting SIL3 applications to enhance the safety of the system.
• 4GB Compact Flash Card: An auxiliary storage module, which allows loading applications without engineering tools, facilitating OEM and remote solutions, and providing additional storage space for system data and programs.

In summary, the modular design of the ABB AC 800M system, with its diverse module types and models, enables flexible configuration according to different industrial scenarios and control requirements. Each module undertakes specific functions, working together to ensure the high availability, reliability and interoperability of the system, making it widely applicable to various industrial fields such as chemical, petrochemical, power generation and water treatment.