Ip Address In Use Detection Function - Mitsubishi Electric MELSEC-L SERIES Basic User Manual

14.6

IP Address in Use Detection Function

If different stations in the same network use the same IP address, the address in use can be detected. This prevents a
network from stopping due to incorrect IP address.
When the connected device with the same IP address does not support the IP address in use detection function, the
error is not detected.
The station that has been already
connected to the network continues
communications even if the station
with the same IP address is connected.
10.97.24.1 (overlapped)
(1) Checking the IP address already in use
The following two methods are available:
• Checking buffer memory areas
• Checking using the Ethernet diagnostics
(a) Checking buffer memory areas
Both the station already connected to the network and the station with the same IP address (station connected
to the network later), and the MAC addresses of the stations with the same IP address can be checked. The
destination IP address can be checked only in the station with the same IP address (station connected to the
network later).
Destination IP address (stored in the station with the same IP address
connected to the network later.)
IP address status
storage area
192
IP address: IP address:
10.97.24.2
MAC address: MAC address:
00 26 92 89 2E 89 00 26 92 45 16 CC
Buffer memory area
The MAC address of the station that has been
already connected to the network (stored in the
station with the same IP address connected to
the network later).
The MAC address of the station with the same IP
address connected to the network later (stored in
the station that has been already connected to
the network).
If a station and another station with the same
IP address exist on the same network, another
station cannot be connected to the network.
(The COM.ERR.LED turns on and COM.ERR.LED
turning on check (X1C) turns on.)
The module
connected later
IP address: IP address:
10.97.24.3 10.97.24.1 (overlapped)
MAC address: MAC address:
00 1A 4D 5D 5D D8 00 26 92 DE 26 90
Buffer memory
address
The third and fourth octets of the IP
234 (EA )
H
address
The first and second octets of the IP
235 (EB )
H
address
The fifth and sixth octets of the MAC
21121 (5281 )
H
address
The third and fourth octets of the MAC
21122 (5282 )
H
address
The first and second octets of the MAC
21123 (5283 )
H
address
The fifth and sixth octets of the MAC
21124 (5284 )
H
address
The third and fourth octets of the MAC
21125 (5285 )
H
address
The first and second octets of the MAC
21126 (5286 )
H
address
This station
cannot be
connected to
the network,
resulting in
an error.
Description