Product Details

Modicon ALU202 (also marked AS-BALU-202) is a robust cpu module and high-performance central processor unit for the Modicon A120 legacy PLC family, originally manufactured under AEG Modicon. This a120 controller acts as the main brain for A120 automation racks, executing ladder logic, scanning local and remote I/O, and managing serial communication with HMI, terminals and supervisory computers. It is equipped with built‑in RS232 and RS485 interfaces and carries 12K RAM for user control programs and register data, supporting continuous process sequencing, interlock protection and mathematical calculations for factory machinery. A backup battery preserves program and runtime data during unexpected power loss, avoiding costly downtime. As a discontinued legacy spare, this cpu module serves as a drop‑in replacement to restore full control capability for ageing A120 control racks without overhauling the whole automation system.

Basic Parameters

Brand: Modicon (AEG legacy)

Model: ALU202 / AS-BALU-202

Product Type: A120 Series Central Processor CPU Module

Compatible Rack: Modicon A120 series backplane and chassis

Memory: 12K RAM

Communication: RS232, RS485 serial ports

Programming Language: Ladder Logic

Mounting: Standard single-slot rack installation

Product Status: Discontinued legacy spare

Net Weight: Approximately 1.18 kg

Supported Functions

This cpu module supports ladder logic upload, download and modification, cyclic I/O scanning and non‑volatile data retention via battery backup. The central processor unit runs onboard self‑diagnostics to detect backplane faults, communication failures and low battery alarms. This a120 controller supports sequential control, analog closed‑loop calculation, alarm logging and remote serial communication, and it can coordinate expansion I/O modules to expand the control scale for complex production lines.

Core Functions

As the dedicated central processor unit, this cpu module interprets and runs all user automation logic, converts field sensor input signals into output commands for actuators, and maintains stable scan cycles for the entire A120 rack. It handles serial data exchange and synchronises all connected I/O nodes. This a120 controller serves as a direct spare to recover primary logic processing for ageing Modicon automation racks.

Hardware Specifications & Environmental Features

Operating Temperature: -10°C ~ +60°C

Storage Temperature: -20°C ~ +70°C

Relative Humidity: 5%–95%, non-condensing

Housing: Heavy-duty shielded industrial metal casing

Protection: Lithium battery data backup, onboard surge suppression

Anti-interference: Isolated serial ports and EMI filtering for noisy plant environments

Compatibility: Matches Modicon A120 series backplane and compatible peripheral modules

Industry Applications: Applied in legacy petrochemical distributed control, old paper making production automation, material handling conveyor lines, packaging and textile machinery, water treatment remote signal collection and large conveyor remote I/O control racks.

Note: Confirm A120 backplane compatibility, battery health, serial wiring and program version before ordering.

This is from our current stock.

available stock.xlsx