User`s manual

105
FX3U Series Programmable Controllers
User’s Manual - MODBUS Serial Communication Edition
12 Troubleshooting
12.5 Checking Setting Contents and Errors
11
Practical Program Examples
12
Troubleshooting
If the correct contents are not stored in the above devices, check the sequence program.
2. Checking for setting errors
1) Error flags
If the parameter settings include an error, the serial communication error flag and the MODBUS
communication error flag turn ON.
Verify that the devices shown in the table below are OFF.
D8420
Channel 2 MODBUS
Communication Format
For Descriptions, refer to Chapter 6.
D8421 Channel 2 MODBUS Protocol
D8429
Channel 2 MODBUS
Slave Response Timeout
D8430
Channel 2 MODBUS
Turn Around Delay
D8431
Channel 2 MODBUS
Message to Message Delay
D8432
Channel 2 MODBUS
Number of Retries
D8434
Channel 2 MODBUS
Slave Node Address
D8435
Channel 2 MODBUS
Communication Status
Information Setup
D8436
Channel 2 MODBUS
Communication Status
Device Range Setup
Device Name Description
M8063 Serial Communication Error 1 (ch1)
Turns ON when abnormality occurs using serial
communication on ch1.
M8402 MODBUS Communication Error on ch1
Turns ON when a MODBUS command error occurs
using ch1.
M8403
MODBUS Communication Error on ch1
(Latched)
Turns ON after a MODBUS command error has
occurred using ch1.
M8422 MODBUS Communication Error on ch2
Turns ON when a MODBUS command error occurs
using ch2.
M8423
MODBUS Communication Error on ch2
(Latched)
Turns ON after a MODBUS command error has
occurred using ch2.
M8438 Serial Communication Error 2 (ch2)
Turns ON when abnormality occurs using serial
communication on ch2.
Device Name Description