Troubleshooting; Checking Communication Status Based On Led Indication; Checking Installation And Wiring - Mitsubishi Electric FX5 User Manual

• Precaution when changing the station number and number of slave stations
Only when the station number and number of slave stations are set with latch setting can the setting values be written to
the corresponding word device from a program or an engineering tool and the setting be changed by powering OFFON
or a system reset. However, be careful not to exceed the range upper limit of device for link device when you set the
device head number. When the device range upper limit is exceeded, the operation is as follows.
(1) When the number of slave stations is increased and the master station link device is insufficient
The error code "7705H" is stored in SD8211, SD9061. However, link continues, but it does not update for the device
above the range upper limit.
(2) When the number of slave stations is increased and the slave station link device is insufficient
The error code "7705H" is stored in SD of the local station of SD8212 to SD8218 and SD9062 to SD9068. However,
link continues, but it does not update for the device above the range upper limit.
(3) When the link device of the local station is out of the device range by changing the slave station number
The error code "7715H" is stored in SD of the local station of SD8212 to SD8218 and SD9062 to SD9068. However,
devices above the range upper limit send all 0 (word: 0, bit: OFF). Also, when the error (7705H) of 2) occurs at the
same time, 7715H is stored.
2.8

Troubleshooting

This section explains troubleshooting.
For the troubleshooting of FX3 Series, refer to the following manual.
FX Series User's Manual - Data Communication Edition

Checking communication status based on LED indication

Check the status of the LED indications of [RD] and [SD] on the CPU module or the communication board/communication
adapter.
LED status
RD
On
On
Off
Off
While N:N Network is executed normally, both LEDs flash brightly.
If the LED are not flashing, check the wiring, master station or other slave station setting.

Checking installation and wiring

• Connection status
The communication cannot be operated if the PLC and the communication board/communication adapter are not
connected correctly.
For the connection procedure, refer to the following.
FX5U User's manual (Hardware)
FX5UC User's manual (Hardware)
• Wiring
Verify that all communication equipment is correctly wired. (Page 19 Wiring)
SD
On
Off
On
Off
Operation status
The data is being sent or received.
The data is received, but is not sent.
The data is being sent, but is not received.
The data is not being sent or received.
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2.8 Troubleshooting
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