Troubleshooting By Symptom; When Cyclic Transmission Cannot Be Performed - Mitsubishi Electric MELSEC iQ-R Series User Manual

4.5

Troubleshooting by Symptom

This section describes troubleshooting method by symptom. If an error has occurred in the master/local module, identify the
error cause using the engineering tool. ( Page 98 Checking the Module Status)

When cyclic transmission cannot be performed

Remote I/O station
Problem Check item
Cyclic data C1-1 Refresh data
cannot be read/ area
written.
C1-2 Parameter
setting
Data cannot be C2-1 Refresh
output from RY. instruction
Description
Have refresh devices been
correctly set in the module
parameters? (RX, RY, SB, SW)
Are the link refresh to refresh
devices using the module
parameters and refresh using a
program (Un\G or FROM/TO
instructions) being performed at
the same time?
Is the correct buffer memory area
being read from/written to? (RX,
RY, SB, SW)
Is any of refresh devices (RX, RY)
of the module parameters set for
the redundant system?
Is a station to which reading/
writing cannot be performed
specified as a reserved station?
Is the refresh instruction executed
after changing parameters by the
dedicated instruction?
Check method
Check if the refresh devices have
been set within the range.
Check if no device overlaps with
ones used in programs or in other
networks.
Note that the number of points of
8-point or 16-point I/O modules
per station is 32 points (fixed)
(excluding number of points set for
the remote I/O station).
• Check the program.
• Check the refresh devices set in
the module parameters.
Check the program. Note that the
number of points of 8-point or 16-
point I/O modules per station is 32
points (fixed) (excluding number of
points set for the remote I/O
station).
Check if any of refresh devices
(RX, RY) is set by mistake for the
redundant system.
Check if the bit corresponding to
the faulty station is not "1" in
'Reserved station specification
status' (SW0074 to SW0077).
Check if 'Refresh instruction when
changing parameters by the
dedicated instruction' (SB0003) is
turned on.
4 TROUBLESHOOTING
4.5 Troubleshooting by Symptom
Action
Correct the refresh device setting.
Set the devices so that they do not
overlap with ones used in
programs and in other networks.
Execute only one of the refresh
processes; either link refresh to
refresh devices using the module
parameters or refresh using a
program (Un\G or FROM/TO
instructions)
• Access the correct buffer
memory area in the
corresponding station.
• Set the devices so that they do
not overlap with ones used in
programs and in other
networks.
• Avoid any refresh devices (RX,
RY) setting for the redundant
system.
• Use program (Un\G) to make
a refresh.
Cancel the reserved station
setting.
Turn on 'Refresh instruction when
changing parameters by the
dedicated instruction' (SB0003).
113
4