Product Details
The ABB PM856A 3BSE066489R1, also cataloged as the PM856A CPU Processor Units, operates as a dedicated hardware component for central application processing and system control execution within ABB AC 800M platforms.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | PM856A |
| Part Number | 3BSE066489R1 |
| Brand | ABB |
| Product Type | CPU Processor Units |
| Origin | Sweden |
| Weight | 0.80 kg |
| Dimensions | 119 x 135 x 185 mm |
| Operating Temp | 0 to +55 deg C |
| Power Consumption | 24 VDC (Backplane power bus) |
| Clock Frequency | 24 MHz |
| System Memory | 16 MB RAM (10.337 MB available for applications) |
| Communication Interfaces | 2 x RJ45 Ethernet ports (CN1, CN2), COM3 (RS-232C), COM4 (Isolated configuration) |
| Expansion Storage | CompactFlash Interface |
| Protection Class | IP20 |
Backplane Bus Communication Velocity and Firmware Flash Compatibility
The processor architecture utilizes a 24 MHz clock frequency to manage real-time control loops and high-throughput data exchanges across connected I/O racks. Dual RJ45 Ethernet ports maintain high backplane bus communication velocity and deterministic network synchronization across Control Network lines. Integrated system logic supports firmware flash compatibility, allowing deterministic program execution, online code changes, and fast diagnostic cycle updates across high-density I/O configurations.
Frequently Asked Questions
Q: What is the available user memory capacity on the PM856A module for control applications?
A: Out of the total 16 MB onboard RAM, 10.337 MB is specifically allocated for user application programs and runtime data storage.
Q: Can the PM856A CPU unit be extracted or inserted under power?
A: No, module removal or insertion must be performed only when the rack power supply is turned off to prevent transient power disruptions on the backplane bus.
Q: How is structural chassis earth grounding established for the CPU unit?
A: Earth ground connection is secured mechanically through the metal DIN-rail clip and rear grounding terminals when locked onto the base plate assembly.
Field Installation Guidelines
- Disconnect all 24 VDC primary power sources before mounting or servicing the PM856A processor unit.
- Wear an anti-static ESD wrist strap grounded to the enclosure frame before handling the module.
- Snap the 0.80 kg module firmly onto the backplane base plate until locking tabs engage completely.
- Torque all module retaining fasteners and connect earth ground straps directly to the cabinet ground bar.
- Maintain a minimum distance of 200 mm between Ethernet/serial lines and 230 VAC/480 VAC power conductors.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
Tech & Buying Guide
The Shift to Flexible IO Modules in Modern Industrial Automation
Traditional control systems rely on dedicated Input Output (IO) cards for industrial automation. Each conventional module processes a single signal type, such as Digital Input (DI), Digital Output (DO), Analog Input (AI), or Analog Output (AO). A standard 16-channel card accepts only one specific channel type across all ports. This inflexible hardware design often creates severe engineering bottlenecks during project execution. Engineers frequently must install entirely new cards to accommodate a single extra sensor. Consequently, late design changes increase control cabinet space requirements and drive up project costs.
DCS Commissioning Steps in Industrial Automation Projects
Commissioning a Distributed Control System (DCS) represents a crucial milestone when deploying modern process automation infrastructure. Field engineers must execute systematic verification steps to transition complex control hardware from static installation to dynamic plant control. Proper commissioning ensures that controllers, I/O modules, network switches, and HMI software operate in strict compliance with engineering design specifications before introducing live process fluids.
PLC and DCS Control System Spares Strategy: Engineering Guidelines
Modern factory automation relies on high-speed fiber optic backbones to link distributed control systems across noise-intensive industrial environments. Unlike copper wiring, optical fibers transmit data via light pulses, making them completely immune to electromagnetic interference (EMI). Field engineers must master optical cable joining and fusion splicing techniques to guarantee low-loss data transmission across critical Programmable Logic Controller (PLC) and Distributed Control System (DCS) nodes.