Data Link Failure In Melsecnet/H Twisted Bus System; Data Link In A Redundant System - Mitsubishi Electric Melsec QJ71LP21 Reference Manual

8 TROUBLESHOOTING

8.2.7 Data link failure in MELSECNET/H twisted bus system

Checkpoint
LINK PARA. ERROR occurs in the CPU module.
Certain normal station does not start data link.
Link scan is slow.
Communication speed cannot be set in the control station.

8.2.8 Data link in a redundant system

Checkpoint
Is the station set for pairing a programmable controller CPU
other than the redundant CPU?
Is the station installed with the redundant CPU preset for
pairing?
Is the station set for pairing a network module of function
version D or later?
Is the station installed with the redundant CPU a network
module of function version D or later?
Is GX Developer used to set network parameters compatible
with the redundant system?
Checkpoint
Is the power supply module on the standby system faulty?
Is the rated voltage supplied to the power supply module on
the standby system?
Is there any stop error in the redundant CPU on the standby
system?
Is there any error in the network module mounted on the
base unit of the standby system?
Is the tracking cable disconnected?
Checkpoint
Has the host station No. +1 or -1 been set to the station to
be paired by pairing setting?
Is the send range of the host station within the tracking
range?
Is any parameter destroyed?
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(1) An error occurs in the redundant CPU
(2) The redundant CPU does not switch the system although the
network module cable is disconnected
(3) Cyclic data are cleared permanently or temporarily in system
switching
Check that the MNET/10 mode is not selected as the network type and
either of the forward and reverse test is not selected as the mode.
Check whether the wiring between connectors are correctly installed. (Refer
to Section 4.6.3 and 4.6.4)
Check whether the "Communication speed setting" of the control station is
correctly set in the network parameter (Refer to Section 5.2.6).
Set network parameters using GX Developer Version 8.78G or later.
Check the CPU model name of the station set for pairing.
Using the device monitoring function of GX Developer, check SW01F8 to
SW01FB for pairing setting.
Install a network module of function version D or later.
Using GX Developer of version 8.18U or later, set network parameters.
Check the external power supply for the standby system.
Connect GX Developer to the redundant CPU on the standby system to
check whether an error exists.
Confirm the status of the network module on the standby system.
Properly connect the tracking cable.
Confirm the number of the station set for pairing.
Confirm that the refresh target devices of the LB/LW within the host station's
send range are set as tracking devices.
Rewrite each parameter using GX Developer. If the symptom remains
unchanged after rewriting, create a new project, and rewrite parameters.
MELSEC-Q
Checking procedure
Checking procedure
Checking procedure
Checking procedure
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