Learn MELSEC-FX-EXTENSIONS with Real Code Examples
Updated Nov 27, 2025
Installation Setup
Install GX Works2 or GX Works3 software
Connect FX PLC via USB, RS-232, or Ethernet
Load FX Extension libraries into project
Configure FX CPU and modules for extension instructions
Download program with extensions to the FX PLC
Environment Setup
Install GX Works2/3 on PC
Connect FX PLC via USB/RS232/Ethernet
Load FX Extension libraries into project
Configure CPU, modules, and communication
Test and monitor program via GX Works online tools
Config Files
GX Works project file (.gwk)
PLC program ladder or structured text files
Function block definition files
I/O configuration and mapping
Communication parameter configuration
Cli Commands
Project compile - verify program syntax
Download to PLC - deploy FX Extension program
Online monitoring - watch variable and I/O states
Start/stop PLC - control execution
Reset PLC - clear errors or restart program
Internationalization
GX Works supports multiple languages
Comments and documentation can be localized
Supports region-specific I/O and communication configurations
Variable naming can follow international standards
Applicable to global industrial deployments
Accessibility
Supported on FX series PLC hardware
GX Works2/3 required for programming and monitoring
Documentation available via Mitsubishi Electric manuals
Community support via forums and user groups
Accessible to automation engineers familiar with FX series
Ui Styling
No native UI for FX Extensions
HMI panels display PLC variables and status
GX Works provides ladder/structured text visual editor
Online monitoring graphs signals and counters
Simulation tools visualize timing and logic
State Management
FX CPU executes tasks sequentially with deterministic scan
Function blocks maintain internal state and parameters
High-speed counters track input pulses asynchronously
PID loops maintain process variables
Communication instructions manage data states
Data Management
Registers store numeric or boolean data
Function blocks handle modular logic and parameters
Arrays and timers manage sequences
I/O mapped to physical devices
Communication instructions exchange structured data