Troubleshooting By Symptom Type - Mitsubishi Electric A1SJ71DN91 User Manual

8. TROUBLESHOOTING
8.1 Troubleshooting Tables
8.1.1

Troubleshooting by Symptom Type

Symptom
No Communication With
Any Slave Station
Determine the appropriate remedy from the symptom of the problem.
Refer to the following tables to determine the appropriate remedy for the symptom.
Check Item
No Communication With Any Slave Station
Is communication cable connected to the DN91 DeviceNet
interface connector?
Are cable locking screws fully tightened?
Check that the communication cable is correctly connected,
referring to 5.5 Connecting Communication Cable to DN91.
Is the network power supply connected? Is the power
turned ON?
Is the network power supply capacity sufficient?
Is the position where the network power supply is connected
OK?
Determine whether the network power supply is connected
to a suitable position, referring to 5.6 Instructions for
Connecting the Network Power Supply.
Does any slave station have the same station number as
the DN91?
Is refresh request (Y(n+1)1) ON?
Is a termination resistance correctly connected to each end
of the network?
Is the same baud rate set for each station?
Does the cable length exceed the permitted limit?
Check the cable length restrictions appropriate for the cable
thickness and baud rate, referring to 3.2 Performance
Specifications.
Check the parameter settings.
Check the error codes.
See 8.3 Troubleshooting using Error Codes.
−
8 2
MELSEC-A
Remedy
Correctly connect the cable.
Turn ON the network power supply.
Replace with a power supply of larger
capacity.
Add a power supply.
Reduce the network load.
Change the position where the network
power supply is connected.
Set the station numbers to avoid
duplication.
Turn ON refresh request (Y(n+1)1) with
a sequence program.
Check if termination resistances are
connected and if they are connected
correctly.
Make sure that the same baud rate is set
for each station.
Reduce the cable length.
Reduce the baud rate.
If thin cable is used in the trunk line,
replace it with thick cable.
See 8.1.2 Problems Due to Incorrect
Parameter Settings
Remedy for error code