Description
The ABB 3BSE085687R1 (specifically the PM862A) is a high-performance CPU module within the ABB Ability™ System 800xA control system. This controller is designed for high-availability, mission-critical process automation.
It is important to note the distinction in your query: You have a PM862A (a high-performance, redundant-capable processor) that was removed from a system that previously utilized a PM851A (a smaller, standard-performance controller).
Technical Comparison: PM862A vs. PM851A
| Feature | PM862A (3BSE085687R1) | PM851A (3BSE066484R1) |
| Performance | High Performance | Standard Performance |
| Memory | Significantly higher (64 MB) | Lower (16 MB) |
| Redundancy | Full Redundancy Support | Full Redundancy Support |
| Application | Large-scale, complex loops | Small to Medium-scale loops |
| Communication | High-speed CEX bus integration | Standard CEX bus integration |
Important Migration/Replacement Notes
- Controller Capacity: The PM862A is a direct upgrade in terms of processing power. If you are replacing a PM851A with a PM862A, you will gain significantly more headroom for your application logic, complex control algorithms, and increased I/O count.
- Project Loading: You cannot simply swap the physical modules and expect the system to function immediately. The hardware configuration in the Control Builder (part of the 800xA engineering software) must be updated. You must change the controller type from PM851A to PM862A in the project tree and re-download the project to the controller.
- Firmware Compatibility: Ensure that the firmware versions running on your CPU and your I/O modules are compatible with the PM862A architecture.
- License Considerations: Verify that your system’s license supports the higher-performance PM862A processor, as some ABB licensing tiers are tied to the controller model.
Key Applications
- Process Industries: Oil & Gas, Chemicals, and Power Generation where sub-millisecond response times for logic execution are required.
- High Availability: Ideal for systems configured in redundant pairs where the PM862A handles complex PID loops and data-intensive communication.
