The Modicon PC-E984-685 is a compact high-performance programmable logic controller (PLC) from Schneider Electric Modicon 984 series. Designed specifically for small and medium-sized industrial automation systems, it features powerful logic operation, data processing, and multi-protocol communication capabilities. It enables centralized equipment control, process monitoring, and network integration, and is widely used in industrial applications such as manufacturing and process control.

Although this controller has been discontinued, it remains in service in numerous existing industrial systems due to its stable, reliable performance and mature ecosystem compatibility. It is fully compatible with the complete range of I/O modules and communication modules in the Modicon 984 series, meeting the expansion and upgrade requirements of complex industrial control systems.

Core Technical Specifications

1. Hardware and Performance Parameters

CPU frequency: 25 MHz 16-bit high-performance processor

Program scan speed: 1 ms/k instructions (1 millisecond per 1000 instructions)

User program memory: 16K words (FLASH memory, non-volatile)

Data memory: 10K words SRAM with power-off retention

System memory: 1MB FLASH + 512KB SRAM for system program and status storage

Local I/O capacity: maximum 16384 I/O points, maximum 1088 register I/O points

Expansion racks: up to 4 expansion racks, compatible with standard 19-inch industrial cabinets

Mounting type: rack slot mounting, supports vertical and horizontal installation

Dimensions: 4×11×9 inches (approx. 101.6×279.4×228.6 mm)

Weight: approx. 4.6 lbs (2.08 kg)

2. Power and Environmental Parameters

Power supply voltage: dual compatible, 24VDC (±10%) / 115/230VAC, 50/60Hz

Rated current: 1.0A at 24VDC; 0.5A at 230VACO

perating temperature: 0℃~60℃ (-20℃~55℃ for some applications)

Storage temperature: -40℃~85℃

Relative humidity: 5%~95% non-condensing

Protection level: industrial standard, suitable for installation in control cabinets

3. Communication Interfaces and Protocols

Modbus ports: 2 ports with RJ45 interface, supporting Modbus RTU/ASCII protocol, used for communication with sensors, actuators, HMI and other devicesModbus Plus port: 1 port with 9-pin D-type interface, supporting Modbus Plus high-speed network for high-speed data exchange and distributed control between controllers

Configuration switches: 2 three-position slide switches for communication parameters + 2 rotary switches for Modbus addressing, used for quick configuration of baud rate, address and other parameters

Status indicators: 6 LED indicators for real-time display of running, communication, fault and other statuses.

Functional Features

Typical Applications