Mitsubishi FX3U-232-BD User Manual

F-73
FX Series PLC User's Manual - Data Communication Edition
Non-Protocol Communication (RS/RS2 Instruction)
11 Troubleshooting
11.4 Checking Sequence Program
A
Common Items
B
N:N Network
C
Parallel Link
D
Computer Link
E
Inverter Communication
F
Non-Protocol Communication (RS/RS2 Instruction)
G
Non-Protocol Communication (FX
2N
-232IF)
H
Programming Communication
I
Remote Maintenance
Apx.
Discontinued models
11.4 Checking Sequence Program
1. Communication settings in a sequence program
Verify that N:N Network (D8176 to D8180) and parallel link (M8070 and M8071) are not set.
Verify that the communication format (D8120, D8400 or D8420) is set correctly. If a communication port is set
more than once, communication is not possible.
After changing any settings, make sure to turn OFF the PLC power, and then turn it ON again.
2. Communication settings using parameters
Verify that the communication settings using parameters are correct. If the contents of the settings do not
agree, communication will not function correctly.
After changing any settings, make sure to turn OFF the PLC power, and then turn it ON again.
3. Presence of VRRD and VRSC instructions (except FX3U and FX3UC PLCs)
Verify that the VRRD and VRSC instructions are not used in the program.
If these instructions are used, delete them, turn OFF the PLC power, and then turn it ON again.
4. Presence of IVCK, IVDR, IVRD, IVWR, and IVBWR instructions (in FX3U and FX3UC PLCs)
Verify that the IVCK, IVDR, IVRD, IVWR and IVBWR instructions are not being used for the same channel.
If these instructions are used for the same channel, revice them, turn OFF the PLC power, and then turn it ON
again.
5. Presence of EXTR instruction (in FX2N and FX2NC PLCs)
Verify that the EXTR instruction is not used in the program.
If this instruction is used, delete it, turn OFF the PLC power, and then turn it ON again.
6. Presence of RS and RS2 instruction
Verify that two or more RS/RS2 instructions are not being driven for the same channel.
If two or more RS/RS2 instructions are driven, modify the program so that only one RS/RS2 instruction is
driven.
11.4.1 Checking communication port settings (in FX3U and FX3UC PLCs)
1. Checking the operation mode
In FX3U and FX3UC PLCs, the communication port operation status can be checked.
D8419 stores the communication type code currently adopted in communication port ch1.
D8439 stores the communication type code currently adopted in communication port ch2.
The table below shows the contents of the communication type codes.
If the operation mode is different, check the parameters and sequence programs.
Code Description
0 Programming communication
2 Protocol dedicated to computer link
3 N:N Network
4RS instruction
5 RS2 instruction
6 Parallel link
7 Inverter instruction

Mitsubishi FX3U-232-BD Specifications

General

Brand	Mitsubishi
Model	FX3U-232-BD
Category	Controller
Language	English