Description
ABB 3BSE018104R1 – AC800M PM856K01
PM856K01 (material number 3BSE018104R1) is the main unit of the on-site controller in the ABB AC 800M series, belonging to the AC801M controller level. Its core function is to serve as the computational and decision-making brain of the entire DCS system, executing control algorithms, processing process data, and coordinating all I/O communications. This module itself does not collect on-site signals, nor does it directly drive actuators. Instead, it interacts with on-site devices through I/O buses and is the core node of the control network in the system architecture.
ABB 3BSE018104R1 – AC800M PM856K01
Computing and storage capabilities
Equipped with a 32-bit RISC real-time multitasking processor and an onboard 8MB RAM, it has error detection and correction functions. Memory is used to store firmware, control unit hardware configuration information, and user applications. On board EPROM (16Kbit) is used to store system boot programs. Equipped with a backup battery to maintain RAM data, the battery voltage is automatically monitored by the module. Built in temperature detection device and Watchdog ensure automatic reset in case of abnormal working conditions. Supports up to 16 concurrent tasks, with a minimum task cycle of 1ms. The SOE sequential event resolution is less than 1ms, meeting the accuracy requirements for event tracing in the process industry.
communication interface
Integrate two IEEE 802.3 Ethernet interfaces, which can be set to redundant mode and have a built-in redundant switching program with a switching time of less than 10ms. Integrate two RS232C interfaces, one for short message transmission (such as programming tool connection) and the other for long message transmission (such as modem control). There is a CEX communication expansion slot on the left side, which can accommodate up to 12 fieldbus expansion modules and supports various protocols such as Profibus DP, Foundation Fieldbus, Modbus, etc. On the right side of the module, up to 8 local I/O stations (non redundant) or 7 I/O stations (redundant configuration) can be connected through the ModulaBus electrical interface, and up to 7 S800 I/O clusters can be connected through the fiber optic ModulaBus. Remote expansion through Profibus DP supports up to 98 remote stations, with a cable transmission distance of 500m (at a speed of 500Kb/s) and a fiber optic transmission distance of up to 2km (at a speed of 12Mb/s). Supports mainstream communication protocols such as Modbus, Siemens 3964R, MasterBus 300, COMLI, as well as additional serial communication protocols for easy integration with terminals, printers, and special controllers. Supports OPC Server service and can communicate with Compact HMI 800 or third-party HMI software.
Programming and Application Management
Programming configuration is carried out through ABB Compact Control Builder software, which complies with the IEC 61131-3 standard and supports five programming languages: ladder diagram (LD), function block diagram (FBD), structured text (ST), sequential function diagram (SFC), and instruction list (IL). The application can be saved and downloaded to the controller through a CF flash card, which is suitable for scenarios where large quantities of repetitive downloads occur in the manufacturing industry. It can also be loaded into the RAM of the target controller through serial port or Ethernet network (RAM requires battery backup), which is more suitable for large-scale program applications. The code can be reused and the feature library can be shared to improve project efficiency.
Electrical and Physical Characteristics
The working power supply is 24V DC, with extremely low power consumption. The onboard power supply has overvoltage protection (OVP), undervoltage protection (UVP), overcurrent protection (OCP), and surge protection. Implement electrical isolation of no less than 2.5kV between the bus side, I/O side, and field side within the module. The onboard LED indicator lights display real-time power status, operating status, error status, battery OK status, and data transmission and reception status of each communication port. There is a reset button. Support hot swapping, replace uninterrupted control output during operation. DIN rail installation, protection level IP20, can be sealed and installed in control cabinets without fans or openings. The working temperature range meets the requirements of industrial sites.
Redundancy capability
Support controller level redundant configuration, achieve bumpless transfer between primary and backup modules, with a switching time of less than 10ms, and control logic is not interrupted and I/O data is not lost during the switching process. Ethernet ports and communication buses both support redundancy, minimizing single point failures to the greatest extent possible.
Typical Applications
The monitoring and auxiliary system control of thermal power and gas turbine units in the power industry, process control and batch control in the petrochemical industry, motor control center and transmission control in the metallurgical industry, and continuous process control in water and papermaking. In the brownfield renovation project, PM856K01 can be used as a standard control unit for the AC800M series, replacing the same level controllers in old systems. It seamlessly connects to existing I/O and field devices through Modulus Bus or Profibus DP, without the need to re plan the communication architecture. Shared with controllers of the same series as PM851, PM860, PM861, and PM864, a unified Compact Control Builder engineering environment can be used for mixed deployment within the same panel.
