LS ELECTRIC iXP2 Series, User Manual

Page: 109 / 132

Appendix 1. Troubleshooting
APP1-9
5. Communication Problems
Question It seems that communication does not work
Phenomenon
On the screen where the object is not many, communication works but when you move the
screen where the object is many, timeout occurs.
< Cause >
(1) In the device setting, the communication time-out is set to be too short.
<Solution>
(1) It occurs because timeout is set much smaller than sum of request time of communication data and
response time from PLC. In the device setting at the XP-Builder, after setting communication time out to
be big, download program and execute again.
Question It seems that communication doesn’t work.
Phenomenon
Communication doesn’t work.
< Cause >
(1) Communication setting or cable may be not normal.
<Solution>
(1) In case of RS-232C, check whether connection setting is normal or not in XP-Builder.
(2) In case of RS-422/485, check whether station and communication connection setting is normal or not.
(3) If 1), 2) is normal, do diagnosis about PLC-RS232C, PLC-RS485/422 at the Serial diagnosis screen of
device menu. Refer to the [Device manual ch.5.6 Serial Communication Diagnosis]
(4) If 3) is normal, check whether connection cable has error or not.
(5) In case of Ethernet, check the port and IP setting about relative PLC.
(6) In case of Ethernet, make sure that the IP and port settings for the other PLC are correct.
Question It seems that communication doesn’t work.
Phenomenon
Ethernet communication is connected slowly after monitoring starts.
< Cause >
(1) Subnet of Ethernet port is the same.
<Solution>
(1) If the subnets of the two Ethernet ports are the same, the initial connection may be delayed due to
the seek time.
(2) If possible, remove the Ethernet port's subnet.