Product Details

Modicon PC-E984-255 is a high-performance compact plc cpu and reliable programmable controller belonging to the Modicon 984 Compact series. This 984 processor unit serves as the central processing core for legacy TSX Compact automation racks, built with 16K words of user logic memory and 24K extended register storage to execute medium-complexity ladder logic programs. It integrates one Modbus serial port and one Modbus Plus peer-to-peer network port, supporting data exchange with remote I/O racks, HMI panels and supervisory control hosts. Featuring a 16 MHz processor and a scan speed of 2.5 ms per K logic, this compact plc cpu delivers steady I/O scanning, arithmetic computation and alarm handling for continuous plant operation. The onboard EEPROM socket and lithium battery backup preserve program and register data during power loss. As a discontinued legacy spare, this programmable controller is widely stocked as a drop-in replacement to restore full system control for ageing Modicon automation racks without complete system upgrade.

Basic Parameters

Brand: Modicon

Model: PC-E984-255

Product Type: Compact 984 PLC CPU Module

Series: Modicon 984 Compact / TSX Compact

Processor Speed: 16 MHz

User Logic Memory: 16K words

Extended Register Memory: 24K words

Scan Rate: 2.5 ms per K logic

Communication: 1 × Modbus port, 1 × Modbus Plus port

Storage Expansion: Socket for EEPROM memory chip

Power Input: 24 VDC

Supported I/O: Up to 64 I/O modules

Programming Software: Concept

Mounting: Standard slot mount for Compact backplane

Product Status: Discontinued legacy spare

Net Weight: Approximately 0.91 kg

Supported Functions

This compact plc cpu supports ladder logic program upload, download and modification, periodic local and remote I/O scanning, and real-time register data retention. The programmable controller runs built-in self-diagnostics to detect backplane faults, communication failures, low battery warnings and memory errors. This 984 processor unit supports sequential interlock control, PID calculation, recipe storage and distributed peer communication over Modbus Plus. It can forward process variables and fault alarms to upper SCADA systems and accept remote setpoint commands, while the memory protection switch prevents unintended program overwriting during field maintenance.

Core Functions

As the primary programmable controller, this compact plc cpu interprets and executes all user automation logic, converts sensor input signals into drive commands for field actuators, and maintains consistent scan timing for the entire rack. It manages both Modbus and Modbus Plus network traffic to synchronise distributed control nodes and remote I/O stations. This 984 processor unit acts as a direct spare to recover central logic processing capability for ageing Modicon automation racks.

Hardware Specifications & Environmental Features

Operating Temperature: 0°C ~ +60°C

Storage Temperature: -20°C ~ +70°C

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

Housing: Compact industrial shielded module casing

Protection: Lithium battery data backup, memory lock switch, onboard transient suppression

Anti-interference: Isolated communication interfaces and EMI filtering for noisy factory power environments

Compatibility: Matches Modicon TSX Compact backplane and compatible peripheral I/O 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 backplane compatibility, memory backup status, network address and program version before ordering.

This is from our current stock.

available stock.xlsx