Mitsubishi Electric MELSEC QS Series User Manual page 136

9
TROUBLESHOOTING
Description of problem
Is the transmission speed
setting of the remote
station correct?
Is the link ID setting of the
remote station correct?
(Safety remote I/O
stations only)
A communication error
Was a correct safety
occurs during
refresh monitoring time
communication with a
set for the scan time?
remote station.
Was a correct safety data
monitoring time set?
Isn't the station No.
overlapped?
9
- 6 9.1 Checking the Condition by Each Problem
Check item Check procedure
Check if the transmission
speed set in network
parameters is matched
with the one set on the
remote station.
Check if the link ID set in
network parameters is
matched with the one set
on the remote station.
Check if any online
operation has been
performed from GX
Developer.
Check special register
SD526 (Maximum scan
time) and calculate
"Safety refresh monitoring
time". (See Section
5.2.1)Check the value set
for the safety refresh
monitoring time.
Check the safety data
monitoring time setting
value.
Check if the maximum
scan time (SD526) is
within the constant scan
time.
Check the station No.
setting of the remote
station.
Check result
Correct the transmission
speed set in network
Not matched parameters or the one set
on the remote station to
make them matched.
Matched Check other items.
Correct the link ID set in
network parameters or the
Not matched one set on the remote
station to make them
matched.
Matched Check other items.
Increase the value set for
Performed the safety refresh
monitoring time.
Not performed Check other items.
Examine the sequence
The calculated "Safety
program and reduce the
refresh monitoring time"
scan time. Or, increase
value is greater than the
the set safety refresh
set value.
monitoring timer value.
In "Constant scan" on
The calculated "Safety "PLC RAS setting" of PLC
refresh monitoring time" parameter, set a value
value is less than the set greater than "Max. scan
value or is appropriate. time".Or, check other
items.
The calculated "Safety Increase the value set for
data monitoring time" is the safety data monitoring
shorter than the set value. timer.
Increase the constant
scan setting value, and
The maximum scan time also correct the value for
(SD526) exceeds the the safety refresh
constant scan time. monitoring timer and the
safety data monitoring
timer.
The station No. is Correct the station No.
overlapped. setting.
The station No. is not
Check other items.
overlapped.
Corrective action