Original ABB high‑performance Plus CPU module for Freelance AC900F distributed control system.

Product Overview

PM904F is the high‑end Plus version CPU core module for ABB Freelance AC900F DCS controller. Equipped with high‑speed RISC processor and expanded application memory, it undertakes real‑time logic computation, PID closed‑loop regulation, interlock processing and multi‑protocol communication management. It supports up to 1500 I/O points, four fieldbus interface slots and optional redundant configuration. Built‑in SD card slot for program backup and firmware upgrade. Widely used as maintenance spare part for petrochemical, power plant, water treatment and process industry DCS control cabinets

Key Features

• 800MHz PowerQUICC II Pro RISC processor, supports complex control logic and rapid loop calculation
• 48MB total memory, 16MB battery‑buffered SRAM for retaining critical process data
• Four 10/100Mbps Ethernet ports, supports Modbus TCP, IEC 60870‑5‑104 protocol
• Two serial interfaces for Modbus RTU / IEC 60870‑5‑101 telecontrol communication
• Four slots for PROFIBUS / CAN fieldbus interface modules, convenient system expansion
• Supports up to 10 units of S700 series direct‑mount I/O modules
• Optional redundant hot‑standby operation for high‑availability process control
• SD‑card slot for offline program backup, restore and firmware update
• Front‑panel LED status indicators and optional LCD display for local diagnosis

• G3‑compliant hardware, adapts to harsh industrial cabinet environment

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Technical Specifications

• Brand: ABB
• Model: AC900F / PM904F
• Module Type: Plus CPU Controller Module
• System Platform: Freelance DCS
• Processor: 800 MHz PowerQUICC II Pro RISC
• Total Memory: 48 MB, 16 MB battery‑buffered SRAM
• Communication: 4×Ethernet, 2×serial port, 4 fieldbus module slots
• Max Direct I/O: 10 pcs S700 I/O modules
• Power Supply: 24VDC
• Power Consumption: 24W
• Operating Temp: 0℃ ~ +60℃
• Storage Temp: ‑40℃ ~ +85℃
• Humidity: 5‑95% non‑condensing

• Installation: DIN‑rail mounting

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Compatibility

Works with ABB Freelance AC900F control system. Firmware matching, application program download and communication loop test required after replacement.