Description
ABB PM891K01 3BSE053241R1 Processor Unit
Product Introduction
In an AC 800M installation where application capacity, Ethernet connectivity, and S800 I/O expansion matter more than a small controller footprint, the ABB PM891K01 3BSE053241R1 provides the processing core for the control application. The PM891 is a monolithic processor unit that integrates the CPU boards, power supply, unit termination, real-time clock, LED diagnostics, INIT pushbutton, Secure Digital interface, CEX-Bus, and optical Modulebus interface. ABB specifies an MPC8270 processor running at 450 MHz with 256 MB of memory and 208.985 MB available RAM for applications.
The ABB PM891K01 3BSE053241R1 provides two RJ45 Ethernet ports for the Control Network and an isolated RJ45 COM4 port intended for configuration/service access. Its optical Modulebus can connect seven S800 I/O clusters, with up to 12 I/O units per cluster, while the CEX-Bus supports communication-interface expansion. The K01 package itself is specified as non-redundant, so procurement teams should distinguish it from PM891K02 when replacing a redundant controller arrangement.
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | PM891K01 |
| ABB Article Number | 3BSE053241R1 |
| Product Type | AC 800M Processor Unit |
| Controller Family | ABB AC 800M |
| Processor Type | MPC8270 |
| Clock Frequency | 450 MHz |
| Memory | 256 MB |
| RAM Available for Application | 208.985 MB |
| Flash Storage | Yes |
| Firmware Flash PROM | 16 MB |
| Power Supply | 24 VDC |
| Permitted Supply Range | 19.2–30 VDC |
| Typical / Maximum Current | 660 / 750 mA |
| Typical / Maximum Power Dissipation | 15.8 / 18 W |
| Ethernet Ports | 2 × RJ45 |
| Ethernet Function | Control Network |
| Serial Port | COM4, isolated RJ45 |
| CEX-Bus | Integrated |
| Optical Modulebus | Integrated |
| I/O Architecture | S800 I/O |
| I/O Cluster Capacity | Up to 7 clusters, up to 12 units per cluster |
| Redundancy | No — PM891K01 is the K01 single-controller package |
| High Integrity | No |
| Application Cycle Time | Down to 1 ms |
| Applications per Controller | 32 |
| Programs per Application | 64 |
| Diagrams per Application | 128 |
| Tasks per Controller | 32 |
| Different Cycle Times | 32 |
| Protection | IP20 |
| Approx. Dimensions | 174 × 186 × 94 mm |
| Approx. Weight | 1.6 kg including base |
| Package Contents | PM891 CPU Module, TB850, TB853 |
| Software License | Not included |
ABB’s current data sheet identifies the article as 3BSE053241R1 (PM891K01) and specifies 450 MHz processing, 256 MB memory, 24 VDC operation, two Ethernet ports, and 208.985 MB of application RAM.
Application Scenarios & Pain Points
Large AC 800M Process-Control Applications
The PM891 was designed for applications where the controller needs more processing and memory capacity than smaller AC 800M processor units. Its 450 MHz processor and 256 MB memory provide substantial application capacity within the AC 800M architecture.
PM891K01 3BSE053241R1
S800 I/O Expansion
The optical Modulebus provides the connection path for S800 I/O clusters. ABB specifies support for seven clusters, each containing up to 12 S800 I/O units. This is important during system expansion because the controller’s I/O architecture, optical Modulebus arrangement, and installed I/O hardware need to be checked together.
Control Network Integration
Two RJ45 Ethernet ports are provided for Control Network connectivity. The ports are part of the controller’s built-in communication architecture, rather than requiring a separate Ethernet communication module for the basic Control Network connection.
CEX-Bus Communication Expansion
The integrated CEX-Bus allows communication-interface units to be added to the controller. ABB also documents the BC810 CEX-Bus interconnection unit for dividing the bus into separate segments where increased communication availability is required.
Related Products
- PM891K02 — redundant PM891 processor-unit configuration; do not treat it as the same ordering package as .
- PM866AK02 — redundant AC 800M processor unit with a different processor/memory configuration.
- PM867K01 — AC 800M high-integrity processor unit; its safety classification differs from .
- PM867K02 — redundant/high-integrity AC 800M processor configuration.
- TB850 — CEX-Bus terminator included with the package.
- TB853 — RCU Control Link terminator included with the package.
- BC810 — CEX-Bus interconnection unit used to divide the communication bus into separate segments.
- — distributed I/O family connected through the controller’s optical Modulebus.
ABB’s controller comparison documentation distinguishes from PM866AK02, PM867K01, and PM867K02 by redundancy, high-integrity classification, processor performance, and memory.
Engineer’s Guide — Field Pitfalls to Avoid
1. Do not confuse with PM891K02.
The K01 is the single-controller package. A redundant system requires the appropriate redundant PM891 architecture and associated interconnection components. Ordering only one K01 as a replacement for a failed member of a redundant configuration can create an incomplete replacement package.
2. Match the complete ABB article number.
Use / 3BSE053241R1 together when requesting a replacement. The PM891 family contains other ordering variants, and the suffix is not cosmetic.
3. Do not assume the processor unit includes a software license.
ABB’s product description explicitly states that the package includes the CPU module, TB850, and TB853, with no license included. The existing Control Builder / System 800xA software environment therefore needs to be checked separately.
4. Check the installed system version before a controller swap.
The processor is only one part of the compatibility question. Verify the installed 800xA/AC 800M software release, controller firmware, application backup, communication modules, CEX-Bus arrangement, and I/O configuration before approving a migration or replacement.
5. Verify the power budget.
ABB specifies 24 VDC operation with a 19.2–30 VDC input range and 660 mA typical / 750 mA maximum current consumption. The controller power requirement should be considered together with the actual cabinet power architecture and any redundant supply arrangement.
6. Do not interpret “supports CPU redundancy” as “K01 is redundant.”
This distinction matters. ABB documents CPU redundancy capability for the platform, while the ordering package itself is identified as Redundancy: No.
FAQ
What is ABB 3BSE053241R1?
It is an AC 800M Processor Unit based on ABB’s processor. The exact article is 3BSE053241R1, and the package includes the CPU module, TB850 CEX-Bus terminator, and TB853 RCU Control Link terminator.
What processor does the use?
ABB specifies an MPC8270 processor operating at 450 MHz. The controller has 256 MB of memory, with 208.985 MB identified as available RAM for applications.
What power supply does require?
The operates from 24 VDC, with an ABB-specified input range of 19.2–30 VDC. Current consumption is listed as 660 mA typical and 750 mA maximum.
How many Ethernet ports does have?
It has two RJ45 Ethernet ports, identified as CN1 and CN2, for connection to the Control Network. It also has an isolated COM4 serial port used for configuration/service purposes.
Can be used with I/O?
Yes. Its optical Modulebus can connect I/O clusters. ABB specifies up to seven clusters, with each cluster containing up to 12 I/O units. The exact installed I/O architecture should still be checked before a controller replacement.
Is a redundant controller?
No. ABB lists as Redundancy: No. The platform supports CPU redundancy when the appropriate redundant system architecture is used, but a K01 should not be described as a redundant processor package.
What is included with 3BSE053241R1?
ABB identifies the package as including the CPU Module, TB850 CEX-Bus Terminator, and TB853 RCU Control Link Terminator. No software license is included.
What should procurement verify before buying a replacement?
Verify , 3BSE053241R1, installed controller firmware/software compatibility, application backup, CEX-Bus configuration, I/O architecture, Ethernet configuration, and the condition of the supplied TB850/TB853 termination hardware. For used or surplus inventory, also verify the actual nameplate, revision, physical condition, and included accessories rather than relying only on a catalog photograph.
