Mitsubishi MELSEC-F FX series programmable controllers

Mitsubishi MELSEC-F FX series programmable controllers

Full list of supported communication hardware

At the beginning of the manual, the full range of FX communication boards (BD), communication adapters (ADP), dedicated function blocks, and conversion modules are listed, divided into four types of interfaces:

RS-232C interface

FX3U-232-BD、FX3U-232ADP (-MB)、FX3G-232-BD、FX2N-232-BD、FX2NC-232ADP、FX0N-232ADP、FX-232ADP、FX2N-232IF（ Independent protocol free dedicated module)

RS-485 interface

FX3U-485-BD, FX3U-485ADP (- MB), FX3G-485-BD/FX3G-485-BD-RJ (RJ45 port 485 board) FX2N-485-BD、FX2NC-485ADP、FX1N-485-BD、FX0N-485ADP、FX-485ADP

RS-422/USB/Ethernet

RS-422：FX3U-422、FX2N-422、FX3G-422、FX1N-422-BD；

USB：FX3U-USB-BD；

Ethernet: FX3U-ENET-ADP;

Conversion module: FX-485PC-IF (485 to PC 232).

Complete description of 15 major categories of FX communication functions

Chapter A of the manual serves as a general foundation, providing a unified introduction to the functions, applicable PLCs, distances, node numbers, and application scenarios of all communication types

1. CC Link fieldbus

Mode: FX as the main station (FX2N/FX3U-16CCL-M), FX as the remote device station (FX2N-32CCL), FX3U intelligent station (FX3U-64CCL); Can interface with A/Q series main stations.

Parameters: Maximum 64 nodes, total length 1200m; compatible with remote IO, servo, and frequency converter.

Applicable: Large scale production line distributed control, upper level network docking.

2. Ethernet communication (FX3U-ENET-ADP)

Only supported by FX3S/FX3G/FX3GC/FX3U/FX3UC, TCP/UDP protocol, 10/100M; functions include program upload and download, online monitoring, and web data browsing.

3. N: N network (multi PLC peer-to-peer RS485 networking, detailed in manual B)

Core: Up to 8 FX PLCs can automatically exchange register M/D through 485, without the need for complex programming.

3 refresh modes (Pattern 0/1/2): Point capacity increases, and the cycle scanning time becomes longer as the number of sites increases.

Hardware: 485BD (total length 50m)/485ADP (total length 500m), terminal resistance 110 Ω.

Exclusive software components: M8176~M8180 station settings, D8201/D8202 scan cycles, communication fault code register.

4. Parallel Link (Manual C)

Only 2 PLCs for one-to-one data exchange, divided into normal/high-speed modes; FX0N/FX1S only supports 50 points M+10 points D, while other models support 100M+10D; Weak scalability, N: N is preferred for multi unit networks.

5. Computer Link (D section, upper computer docking)

RS232 one-to-one (15m), RS485 one to many (up to 16 PLCs, 500m); The computer uses specialized instructions (BR/WR/QW, etc.) to read and write PLC bits/words, remotely start and stop, and read machine models; Supports two communication protocols in 1/4 format.

6. Communication of frequency converter (Part E, Mitsubishi FREQROL series)

Up to 8 Mitsubishi inverters can be mounted on the RS485 bus; The old model FX2N uses the EXTR command, while FX3G/3U/3S has dedicated IV series commands (IVCK/IVDR/IVRD/IVWR/IVBWR/IVMC); Read and write frequency, current, fault code, and all parameters.

7. Protocol free communication (F RS/RS2, G FX2N-232IF)

Universal serial port transparent transmission, compatible with barcode scanners, instruments, printers, and third-party controllers;

RS: Single channel basic without protocol;

RS2: Dual channel, supports checksum, start and end symbols, multiple control signal lines;

FX2N-232IF independent module: large capacity cache, suitable for high-frequency transmission and reception.

8. MODBUS serial communication

FX3S/3G/3G/3U support, relying on 485ADP-MB/232ADP-MB, can be used as a master/slave station to interface with third-party Modbus instruments and frequency converters.

9. Programming Communication (Chapter H, Program Upload and Download)

PLC with built-in RS422 port USB、 232/485 expansion board, connected to GX Works2/GX Developer/FXGP handheld panel; Support online monitoring, forced IO, and program read/write.

10. Remote Maintenance Part I

PLC side and computer side are connected with modems, and telephone lines are used for remote uploading/monitoring of programs. Only FXGP supports file transfer between computers.

11. I/O provincial bus

CC Link/LT (built-in to FX3UC-32MT-LT), AnyWireALSINK, AS-i bus, remote distributed IO, reducing control cabinet wiring.

12. Email sending

Internet mail: FX-232DOPA module sends mail to computer/mobile phone;

Short message: The old FX2N sends an alert message to NTT mobile phones in Japan via modem (limited to local devices in Japan).

General core setting method for communication

FX PLC has two communication configuration methods, with parameter setting taking priority over program assignment:

Programming software parameter configuration (recommended)

Select communication enable on the GX Works2/FXGP software PLC parameter interface, configure baud rate, data bits, parity, and station number; After downloading the parameters, power off and restart to take effect; FX0/FX2 old models are not supported.

Ladder diagram program assignment

Write special data registers (D8120/D8370/D8420, etc.) using MOV instructions to configure the serial port format. Rewrite takes effect in RUN mode; Universal across the entire series.

Channel differentiation: FX3G/3U multi-channel (CHO/CH1/CH2), different channels can independently configure different communications, but there are functional mutual exclusion restrictions (such as CH1 using N: N, CH2 cannot open parallel links).

Detailed Chapters by Module Core Content

Chapter B N: N Network

Implementation process: Confirm model version → Hardware selection → 485 wiring → Terminal resistance setting → Software parameter configuration → Communication testing → Writing interactive program → Troubleshooting;

Three refresh mode point allocation tables, specifying the exclusive M and D register intervals for stations 0-7;

Provide complete master and slave standard example programs;

Troubleshooting: LED light status, wiring inspection, parameter verification, communication error codes.

Chapter C Parallel Link

One on one data exchange, distinguishing between normal/high-speed modes, dedicated M8070/M8071 master-slave flags, D8070 timeout register, with practical examples and fault location attached.

Chapter D Computer Link

Complete upper communication instruction set (bit read/write, word read/write, remote RUN/STOP, loop testing, etc.); Detailed explanation of communication timing, frame format, and NAK error codes, supporting RS232/485 wiring schemes.

Chapter E Frequency Converter Communication

Distinguish between the FX2N old-fashioned EXTR instruction and the FX3 series dedicated IV instruction; Covering frequency converter parameter reading and writing, operation monitoring, and batch parameter writing; Compatible with the entire series of Mitsubishi variable frequency drives S500/E700/A800, with multiple sets of practical programs included.

F/G chapter protocol free communication

The sending and receiving buffer, start symbol, stop symbol, and verification configuration of RS/RS2 instructions; Control pin timing; FX2N-232IF module BFM cache all address definitions, send and receive cache partition instructions.

Chapter H Programming Communication

Selection of various programming cables and conversion heads, GX Works computer connection steps, communication timeout and retry parameter settings, and troubleshooting solutions for online failures.

Chapter I Remote Maintenance

Modems AT command configuration, telephone line networking steps, remote online operation process, communication troubleshooting.

Unified standard for hardware cabling

Cable: RS485 recommended shielded twisted pair, divided into 0.2/0.3/0.5mm ² specifications; FX3G-485-BD-RJ can use Category 5e shielded Ethernet cables;

Terminal resistance: 110 Ω terminals must be connected at both ends of the bus, and the BD board comes with a dip switch for switching;

Terminal specifications: distinguish between European terminals and M3 terminals, specify wire diameter, stripping length, tightening torque, and matching screwdriver model;

Grounding: Communication shielding layer single ended Class D grounding, grounding resistance ≤ 100 Ω, power equipment common grounding is prohibited.

Version, Tools, and Supporting Manuals

PLC version check: Read the last three digits of the special register D8001 or the LOT production number on the body nameplate to determine the year and month;

Programming software adaptation: GX Works2, GX Developer, FXGP/WIN, FX-30P handheld panel, minimum supported version list for each model; Old PLCs can be replaced by software and compatible with programming models;

Classification of supporting materials:

Hardware manual: PLC body, communication BD/ADP installation manual;

Programming Manual: Basic/Application Instructions;

Special Communication Manual: MODBUS Special Manual, CC Link Sub Manual;

Peripheral manuals: touch screen, modem, and communication conversion module manuals.

General logic for troubleshooting

Five steps for unified investigation:

Check if the PLC firmware and software version support the current communication function;

Check the RD/SD indicator lights on the communication module to determine the sending and receiving status;

Check wiring, terminal resistance, shielding grounding, and strong and weak electrical isolation;

Verify software parameters/serial port register configuration within the program;

Read the dedicated fault M and D registers, refer to the error codes in the manual to locate communication timeouts, verification errors, site conflicts, and other issues.

Key Limitations and Precautions

Multi channel mutual exclusion: N: N and parallel links cannot be enabled simultaneously; Some functions are only supported by CH1 and cannot be configured for CH2;

Module power supply limitation: Communication BD/ADP occupies the PLC expansion 5V current, and multiple module stacking overload requires the installation of FX3UC-1PS-5V power module;

Model difference: FX0/FX2/FX1S old models only support a small amount of basic communication, while FX3U/FX3GC has the most comprehensive functions;

Copyright Disclaimer: The manual does not grant patent usage rights, Mitsubishi is not responsible for equipment failures caused by example programs, and specification revisions are not notified in advance.