ABB PM877 3BDH000777R1 | Redundant Processor Unit

1 x Onet, 1 x red. Cnet (C), 2 x red. Fnet, 2 x DPV2, 1 x Eth – with current SW version – up-, downgrade of FW via USB-Stick or Analyzer possible – PROFIBUS DP release only with License !
– Redundancy Link Cable NT 031 necessary for redundant controller

Central_Unit

298 mm

400 mm

130 mm

0.95 kg

Working Principle

1. Data Acquisition and Input Processing

• Input Interfaces: Receives field signals (e.g., temperature, pressure, switch status) through built-in or extended I/O modules (e.g., Analog Input AI, Digital Input DI).
• Signal Conditioning: Preprocesses input signals through filtering, amplification, and analog-to-digital conversion (A/D conversion) to ensure data accuracy.
• Real-Time Guarantee: Uses high-speed sampling technology to ensure timely response to dynamic signals (typical cycle in milliseconds).

2. Control Logic and Algorithm Execution

• Program Runtime Platform: Based on a Real-Time Operating System (RTOS) to ensure deterministic execution of control programs (no delays or priority preemption).
• Programming Language Support: Compatible with IEC 61131-3 standard programming languages (e.g., Ladder Diagram LD, Structured Text ST, Function Block Diagram FBD), allowing users to write control logic as needed.
• Algorithm Processing:
  • Performs conventional logic control (e.g., interlock protection, sequential control).
  • Supports advanced control algorithms (e.g., PID regulation, fuzzy control, complex mathematical operations).
  • Handles specific algorithms for motion control or process control (e.g., motor speed regulation, process optimization).

3. Output Control and Execution

• Output Interfaces: Sends control commands through analog output (AO), digital output (DO), and other interfaces.
• Signal Conversion: Converts digital signals to analog signals (D/A conversion) or directly drives actuators such as relays and transistors.
• Closed-Loop Control: Forms a closed-loop control circuit by integrating feedback signals (e.g., real-time sensor data) to dynamically adjust outputs and achieve target parameters.

4. Communication and System Integration

• Internal Communication: Exchanges real-time data with expansion modules (e.g., I/O modules, communication modules) via backplane buses or dedicated interfaces.
• External Communication:
  • Supports industrial Ethernet (e.g., PROFINET, EtherNet/IP, Modbus TCP) and fieldbus (e.g., PROFIBUS, CANopen) protocols.
  • Communicates with upper computers (SCADA systems, HMI human-machine interfaces), other controllers, or cloud platforms to enable data monitoring, remote configuration, and system collaboration.

5. System Management and Diagnostics

• Real-Time Operating System (RTOS): Manages task scheduling, memory, and interrupt handling to ensure the stability of parallel multi-task operations.
• Fault Diagnosis:
  • Built-in self-test functions (e.g., hardware fault detection, program runtime monitoring).
  • Feeds back anomalies (e.g., communication interruptions, power failures, overloads) via LED indicators, diagnostic logs, or upper computer interfaces.
• Redundancy and Reliability: Some models support hot redundancy configuration (e.g., dual controllers backing up each other) to ensure system continuity in the event of single-point failures.