Description
Product Core Brief
- Model: PM876-1 3BDH000707R1
- Brand: ABB
- Series: AC 800M
- Core Function: Executes process control and logic for AC 800M / 800xA systems with S800 I/O and CEX-bus communication.
- Product Type: Processor Module (CPU)
- Key Specs: 24 V DC supply | 0 to +55 °C operating range | Ethernet + CEX-bus + ModuleBus
- Condition: New Surplus
Product Introduction
ABB PM876-1 3BDH000707R1 is an AC 800M processor module for mid-to-high performance process control. It runs Control Builder M applications, manages S800 I/O over ModuleBus, and supports Ethernet plant/control networking plus CEX-bus communication expansion.
This unit fits systems that need stable CPU redundancy, hot-swappable maintenance, and deterministic task execution. Typical AC 800M CPUs support task cycles down to 1 ms and redundancy switchover in the single-digit to sub-100 ms range depending on configuration.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Brand | ABB |
| Model | |
| Part Number | 3BDH000707R1 |
| Series | AC 800M |
| Product Type | Processor Module (CPU) |
| Supply Voltage | 24 V DC nominal |
| Operating Temperature | 0 to +55 °C |
| Ethernet Ports | 2 × 10/100 Mbps (IEEE 802.3) |
| Serial Interfaces | 2 × RS-232C (COM3/COM4) |
| I/O Connection | S800 I/O via ModuleBus |
| Communication Expansion | CEX-bus (CI8xx modules) |
| Redundancy | Supported with SM8xx synchronization module |
| Mounting | DIN-rail on AC 800M baseplate |
| Condition | New Surplus |
Quality Control Process
- Visual inspection: Check the PCB, connectors, CF card slot, LED indicators, and baseplate pins for corrosion, bent contacts, or mechanical stress.
- Power-up self-test: Apply 24 V DC on a test baseplate and verify LED sequences, watchdog behavior, and clean boot without fault flashes.
- Communication check: Validate both Ethernet ports and serial interfaces; confirm link stability and basic TCP/serial response.
- ModuleBus/CEX-bus verification: Confirm the processor can address S800 I/O segments and recognize CEX-bus communication modules where available.
- Redundancy and firmware review: If configured, verify primary/secondary handshake with the synchronization module and confirm firmware/boot integrity. Pack in anti-static bags with edge protection.
Replacement Pitfall Guide
❗ Verify the exact part number. PM876 units may carry different suffixes and order codes. 3BDH000707R1 must match your spare list, firmware compatibility, and redundancy configuration.
❗ Don’t assume direct interchange with PM864/PM865/PM891. Memory, CEX-bus limits, ModuleBus behavior, and redundancy rules can differ. Always check the AC 800M hardware manual before cross-substitution.
❗ Watch the redundancy constraints. In redundant CPU configurations, COM3 and electrical ModuleBus may be restricted. Wrong cabling or baseplate setup can block synchronization.
❗ Confirm the baseplate and power budget. The processor needs a compatible AC 800M baseplate, proper 24 V DC supply, and sufficient backplane power for all attached I/O and CEX modules.
Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
| Original Model | Replacement / Successor Model | Compatibility Level | Migration Notes |
|---|---|---|---|
| ABB PM876-1 3BDH000707R1 | ABB PM876-1 (matching order code) | Direct | Verify firmware, redundancy kit, and baseplate compatibility. |
| ABB PM876-1 3BDH000707R1 | ABB PM891 | Needs Adaptation | Different hardware platform; review CEX-bus, ModuleBus, power, and firmware migration. |
| ABB PM876-1 3BDH000707R1 | ABB PM866 / PM865 | Needs Adaptation | Legacy AC 800M CPUs; verify memory, task load, I/O mapping, and redundancy modules. |
Benchmarks:
- Minimum task cycle: 1 ms for AC 800M controllers; SOE resolution typically under 1 ms.
- Redundancy switchover: typically under 100 ms, depending on I/O layout and synchronization configuration.
