Product Details:

MODICON ALU821, originally released under AEG Modicon, is a legacy rack mounted CPU processor module for classic AEG Modicon automation control platforms. It serves as the core processing unit of the control rack, responsible for executing user control programs, scanning local and remote I/O signals, running sequence logic and closed-loop regulation for process equipment. This processor is equipped with multiple serial communication interfaces to connect operator panels, remote I/O racks and upper monitoring systems for program download, real-time data exchange and alarm transmission. It adopts standard backplane rack installation and can work cooperatively with matched AEG Modicon I/O modules and power supplies. The circuit board uses industrial grade components with built-in surge suppression and EMC filtering to withstand continuous operation under electromagnetic interference in factory environments. As an obsolete original spare part, it is mainly used for maintenance and retrofitting of aging AEG Modicon control systems. Direct replacement retains the original program, wiring layout and network architecture, avoiding large-scale system reconstruction and reducing production downtime.

Basic Parameters

Product type: AEG Modicon legacy rack CPU processor module

Processor: 32-bit processor with floating point support

Max I/O capacity: up to 2048 I/O points

Program memory: 256 KB flash

Data memory: 128 KB SRAM

Installation: rack mount for AEG Modicon backplane

Communication: RS232, RS485

Operating temperature: 0°C ~ +60°C

Protection grade: IP20

Supported Functions

User logic program scanning and execution

Local and remote I/O data acquisition and output

Floating-point arithmetic and PID regulation

Serial communication with HMI and remote racks

Program upload and download

Battery-backed data retention

Core Functions

Real-time logic calculation and sequence control

Onboard multi-status LED indication

Communication frame parsing and forwarding

Fault and diagnostic code storage

Remote programming access

Watchdog protection for program runaway

Hardware Specifications & Environmental Features

Built-in surge and noise suppression circuit

Storage temperature: -25°C ~ +70°C

Relative humidity: 5% to 95% non-condensing

Status: Obsolete original part, available for spare replacement

Industry Applications: Applied in legacy metallurgical process control, old paper making production lines, conventional power plant auxiliary control and large material handling automation racks.

Note: Confirm backplane compatibility, program memory requirement and serial cable definition before ordering.

This is from our current stock.

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