Factory Automation

MELSEC-F series Computer Link

Features

Data link can be made between computer as master station and multiple PLCs.
Because data link is performed by commands sent from the computer, this is suitable for management and control systems where the computer is the main controller.

  1. 1.Using RS-485 communication devices, up to 16 FX and A PLCs can be connected and send/receive data according to commands from a computer.
  2. 2.Using RS-232C communication devices, data can be sent/received 1:1 with a computer.
  3. 3.Protocol supports PLC's computer link dedicated protocol (formats 1 and 4).

Applicable communication device

RS-232C communication device

Model Applicable FX PLC
FX
3S		 FX
3G		 FX
3U		 FX
3GC		 FX
3UC
Function expansion board FX3G-232-BD *5
○
Max.
1 unit		 ○
Max.
2 units
*1		 × × ×
FX3U-232-BD × × ○
Max.
1 unit		 × *2
○
Max.
1 unit
Specific adapter FX3U-232ADP-MB *6
○
Max.
1 unit		 *3
○
Max.
2 units
*1		 *4
○
Max.
2 units		 ○
Max.
2 units		 *4
○
Max.
2 units
  • *1FX3G 14 pt, 24 pt models: 1 board. 40 pt, 60 pt models: 2 boards.
  • *2Can be connected only to the FX3UC-32MT-LT(-2).
  • *3When connecting to FX3G, FX3G-CNV-ADP is required.
  • *4When connecting to FX3U, FX3UC-32MT-LT(-2), function expansion board is required.
  • *5Function expansion board and FX3S-CNV-ADP cannot be used together.
  • *6When connecting to FX3S, FX3S-CNV-ADP is required.

RS-485 communication device

Model Applicable FX PLC
FX
3S		 FX
3G		 FX
3U		 FX
3GC		 FX
3UC
Function expansion board FX3G-485-BD *5
○
Max.
1 unit		 ○
Max.
2 units
*1		 × × ×
FX3G-485-BD-RJ *5
○
Max.
1 unit		 ○
Max.
2 units
*1		 × × ×
FX3U-485-BD × × ○
Max.
1 unit		 × *2
○
Max.
1 unit
Specific adapter FX3U-485ADP-MB *6
○
Max.
1 unit		 *3
○
Max.
2 units
*1		 *4
○
Max.
2 units		 ○
Max.
2 units		 *4
○
Max.
2 units
  • *1FX3G 14 pt, 24 pt models: 1 board. 40 pt, 60 pt models: 2 boards.
  • *2Can be connected only to the FX3UC-32MT-LT(-2).
  • *3When connecting to FX3G, FX3G-CNV-ADP is required.
  • *4When connecting to FX3U, FX3UC-32MT-LT(-2), function expansion board is required.
  • *5Function expansion board and FX3S-CNV-ADP cannot be used together.
  • *6When connecting to FX3S, FX3S-CNV-ADP is required.

System configuration example

1 : N connection using the RS-485 (422) communication

System configuration example

1 : 1 connection using the RS-232C communication

System configuration example

Specifications

Items Specifications
Transmission standard Conforming to RS-485 (RS-422) or RS-232C standard
Total extension length RS-485 When special adapter is used: 500 m
When function expansion board is used (including when special adapter and function expansion board are used together): 50 m
RS-232C 15 m
Communication method Half-duplex bidirectional
Transmission speed FX3S, FX3G, FX3U,
FX3GC, FX3UC		 300/600/1200/2400/4800/9600/19200/38400 bps*1
Number of connectable units RS485 : Max. 16 units, RS-232C : 1 unit
Protocol types MELSEC-A computer link protocol format 1, 4 (some restrictions)
RS-485
(RS-422)
connection device		 FX3S FX3G-485-BD(-RJ), or FX3S-CNV-ADP + FX3U-485ADP-MB
FX3G FX3G-485-BD(-RJ), or FX3G-CNV-ADP + FX3U-485ADP-MB
FX3GC FX3U-485ADP-MB
FX3U, FX3UC*2 FX3U-485-BD, or function expansion board + FX3U-485ADP-MB
RS-232C
connection device		 FX3S FX3G-232-BD, or FX3S-CNV-ADP + FX3U-232ADP-MB
FX3G FX3G-485-BD, or FX3G-CNV-ADP + FX3U-232ADP-MB
FX3GC FX3U-232ADP-MB
FX3U, FX3UC*2 FX3U-232-BD, or function expansion board + FX3U-232ADP-MB
Applicable FX PLC FX3G, FX3U, FX3GC, FX3UC
A Computer link protocol unit
  • *1For FX3U and FX3UC, 38400 bps transmission speed is supported in Ver. 2.41 or later.
  • *2For FX3UC-**MT/D, FX3UC-**MT/DSS, and FX3UC-16MR/D(S)-T, function expansion board cannot be connected. Special adapter can be directly connected.