Description
🔧 Product Overview
The ABB PM891K01 is a high-performance processor unit for the ABB AC 800M controller platform and System 800xA automation environments.
With a 450 MHz processor and 256 MB memory, PM891K01 is positioned at the high-performance end of the standard AC 800M processor range. ABB specifies a processing performance of 0.043 ms for 1,000 Boolean operations, making it suitable for demanding control applications with relatively large application programs and extensive I/O configurations.
The unit integrates the CPU, power supply, termination, RAM, real-time clock, Ethernet interfaces, CEX-Bus and optical ModuleBus functions into a single controller assembly.
⚙️ Main Features
- ABB AC 800M Processor Unit
- Model: PM891K01
- Article number: 3BSE053241R1
- 450 MHz processor
- 256 MB memory
- 208.985 MB RAM available for application
- MPC8270 processor
- 2 × RJ45 Ethernet ports
- 10/100 Mbit/s Ethernet
- 1 × isolated RJ45 COM4 serial port
- Built-in CEX-Bus
- Optical ModuleBus support
- Supports up to 7 optical I/O clusters
- Up to 84 S800 I/O modules on ModuleBus
- 24 VDC power supply
- Built-in real-time clock
- Secure Digital interface
- LED status indicators
- No internal backup battery
- Designed for AC 800M / System 800xA applications
📋 Product Datasheet
| Parameter | Specification |
|---|---|
| Brand | ABB |
| Model | PM891K01 |
| Article Number | 3BSE053241R1 |
| Product Type | AC 800M Processor Unit |
| Controller Family | AC 800M |
| System | ABB System 800xA |
| Processor | MPC8270 |
| Clock Frequency | 450 MHz |
| Memory | 256 MB |
| Application RAM | 208.985 MB |
| Performance | 0.043 ms / 1,000 Boolean operations |
| Redundancy | No – single processor unit |
| Power Supply | 24 VDC |
| Supply Range | 19.2–30 VDC |
| Typical Current | 660 mA |
| Maximum Current | 750 mA |
| Typical Power Dissipation | 15.8 W |
| Maximum Power Dissipation | 18 W |
| Ethernet Ports | 2 |
| Ethernet Speed | 10/100 Mbit/s |
| Ethernet Protocols | MMS / IAC Control Network |
| Serial Port | Isolated COM4 |
| CEX-Bus | Integrated |
| CEX-Bus Communication Modules | Up to 12 |
| Optical ModuleBus | Up to 7 clusters |
| Maximum S800 I/O Modules | Up to 84 |
| Internal Backup Battery | No |
| Protection Class | IP20 |
| Dimensions | Approx. 174 × 186 × 94 mm |
| Weight Including Base | Approx. 1.6 kg |
ABB’s official hardware selector confirms the PM891K01 article number, processor, memory, 24 VDC supply range, Ethernet interfaces, CEX-Bus capacity, ModuleBus capacity and physical dimensions.
🧠 Processor and Memory Architecture
The PM891 processor is a monolithic controller assembly containing the processor electronics, RAM, power supply and unit termination.
The 450 MHz processor provides a 0.043 ms execution time for 1,000 Boolean operations. The controller has 256 MB of memory, with approximately 208.985 MB available for application use according to ABB’s current hardware data.
This makes PM891K01 appropriate for AC 800M projects where the controller needs more processing capacity and application memory than earlier PM85x/PM86x processor generations.
🌐 Ethernet & Control Network
PM891K01 includes two RJ45 Ethernet interfaces, designated CN1 and CN2.
The interfaces operate at 10/100 Mbit/s and provide connection to the AC 800M Control Network. ABB identifies MMS and IAC as the principal Control Network communication protocols.
A separate isolated COM4 RJ45 serial port is provided for configuration and service functions.
🔌 CEX-Bus and Communication Expansion
The CEX-Bus is integrated into the PM891 processor unit.
It allows additional communication interface modules to be connected to the controller. ABB specifies support for up to 12 communication modules on the CEX-Bus, with redundant communication interfaces possible depending on the system architecture.
For larger AC 800M installations, the BC810 CEX-Bus interconnection unit can be used to divide the communication bus into separate segments.
🔗 S800 I/O Integration
PM891K01 supports ABB S800 I/O through its optical ModuleBus architecture.
ABB specifies:
- Up to 7 optical I/O clusters
- Up to 12 S800 I/O units per cluster
- Maximum 84 S800 I/O modules
- ModuleBus scan time from 0–100 ms depending on the number of connected I/O modules
This makes the processor suitable for distributed I/O architectures where field I/O is located away from the controller cabinet.
⚡ Power Supply
The PM891K01 operates from a 24 VDC supply, with an allowable range of 19.2–30 VDC.
ABB specifies typical current consumption of 660 mA and maximum current consumption of 750 mA. Maximum power dissipation is specified as 18 W.
The controller also provides a redundant power-supply status input for applications requiring power-supply monitoring.
🏭 Typical Applications
PM891K01 can be used in AC 800M control architectures such as:
- Process automation
- Oil and gas control systems
- Power generation
- Chemical processing
- Water and wastewater
- Mining and metals
- Pulp and paper
- Distributed I/O control
- System 800xA automation systems
- Large PLC/DCS control applications
The controller is especially relevant where an existing AC 800M installation requires a higher-performance processor with substantial application memory.
🔩 Installation & Configuration
Before installation, verify the complete article number and controller configuration.
Recommended procedure:
- Switch the control system to the appropriate maintenance state.
- Isolate the controller power according to site procedures.
- Verify the PM891K01 identification and article number.
- Check the mounting/base arrangement.
- Connect the 24 VDC supply correctly.
- Connect Ethernet CN1/CN2 according to the Control Network design.
- Connect required CEX-Bus communication modules.
- Connect the S800 I/O architecture through the appropriate ModuleBus configuration.
- Verify firmware and controller configuration.
- Restore power and check the controller LEDs.
- Confirm communication with the engineering/configuration environment.
- Verify I/O communication before returning the process to normal operation.
Configuration should be performed using the appropriate ABB engineering tools and the software version supported by the installed AC 800M/System 800xA environment.
🔄 PM891K01 vs PM891K02
This distinction is important when purchasing a replacement.
PM891K01 — 3BSE053241R1
- Single PM891 processor unit
- 450 MHz
- 256 MB
- No built-in CPU redundancy
- Package includes PM891 CPU Module, TB850 CEX-Bus terminator and TB853 RCU Control Link terminator
PM891K02 — 3BSE053242R1
- Redundant processor package
- Uses two PM891K01 processor units
- Includes TK850V007, TK855 and TK856 cables
- Designed for redundant CPU operation
ABB’s product catalog explicitly lists PM891K01 as the single Processor Unit and PM891K02 as the Redundant Processor Unit.
Therefore, PM891K01 should not be advertised as a complete redundant controller package. It is the processor unit used individually or as one of the two processors in a PM891K02 redundancy arrangement.
🔄 Compatibility & Replacement Notes
PM891K01 belongs to the AC 800M processor family. Related processor models include PM851, PM856, PM857, PM858, PM860, PM862, PM863, PM866, PM867 and PM891 variants.
A replacement should not be selected by physical appearance alone. Check:
- Article number
- Processor generation
- Firmware/software compatibility
- Memory requirements
- Redundancy requirements
- CEX-Bus configuration
- ModuleBus configuration
- System 800xA version
- Existing application configuration
For a redundant PM891 installation, two compatible PM891 processor units and the appropriate redundancy accessories are required.
❓ Frequently Asked Questions
Q: What is ABB PM891K01?
A: It is a high-performance AC 800M Processor Unit for ABB automation and System 800xA environments.
Q: What is the ABB article number?
A: The article number is 3BSE053241R1.
Q: Is PM891K01 redundant?
A: No. PM891K01 is the individual processor unit. PM891K02 is ABB’s redundant processor package.
Q: What processor does PM891K01 use?
A: ABB specifies an MPC8270 processor running at 450 MHz.
Q: How much memory does it have?
A: The controller has 256 MB memory, with approximately 208.985 MB available for applications.
Q: What is the power supply?
A: 24 VDC, with an ABB-specified operating range of 19.2–30 VDC.
Q: How many Ethernet ports are available?
A: Two RJ45 Ethernet ports are integrated into the PM891.
Q: Does it have a backup battery?
A: No. ABB specifies that the PM891 does not contain an internal backup battery.
Q: Can PM891K01 be used as part of a redundant system?
A: Yes. Two PM891K01 processor units form the processor portion of the PM891K02 redundant package when the required redundancy hardware and configuration are provided.
Q: Is the license included?
A: ABB’s product catalog states that no license is included with the PM891K01 package.
🔧 Recommended ABB AC 800M Models
- ABB PM851AK01 Processor Unit
- ABB PM856AK01 Processor Unit
- ABB PM857K01 High Integrity Processor Unit
- ABB PM857K02 Redundant Processor Unit
- ABB PM858K01 Processor Unit
- ABB PM858K02 Redundant Processor Unit
- ABB PM862K01 Processor Unit
- ABB PM866AK01 Processor Unit
- ABB PM867K01 High Integrity Processor Unit
- ABB PM891K02 Redundant Processor Unit
These models belong to the ABB AC 800M processor/controller family; PM891K02 is the direct redundant-package counterpart to PM891K01.
🧪 Inspection Before Shipment
For a PM891K01 intended as an industrial replacement spare, inspection should include:
- Exact model and article-number verification
- Nameplate inspection
- PCB and housing inspection
- Ethernet connector inspection
- COM4 connector inspection
- SD interface inspection
- LED status inspection
- Mounting/base condition
- Connector and terminal inspection
- Firmware/version verification where possible
- Power-up diagnostic test
- Communication test
- Controller configuration verification
- ESD-safe packaging
For replacement applications, the most important identification is:
ABB PM891K01 → Article No. 3BSE053241R1 → 450 MHz → 256 MB → Single Processor Unit.
ABB’s current documentation confirms these core specifications and clearly distinguishes this model from the PM891K02 redundant processor package.
