6 Message Communications
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CJ-series PROFINET IO Controller Unit Operation Manual for NJ-series CPU Unit (W511)
6-4
Command Message Routing
Command Messages to TCP/IP Address
The command message address is replacing the last octet of the PROFINET IO Controller’s own IP-
address. If the IO Controller has the IP-address 192.168.1.5 and the command message destination
address is 45 then the destination IP-address will be 192.168.1.45.
Address Range
The order of determining the IP-address from the command message address is first IO Device
Number and then the replacement of the last octet of the IO Controller’s own IP-address. The PRO-
FINET IO Controller does not hold an address translation table. As the highest command message
address is 127 and the maximum amount of IO Devices supported is 126 the highest IP-address
that can be addressed is 127.
In the example above the highest IP-address is 192.168.1.127.
Performance
The CJ1W-PNT21 PROFINET IO Controller’s main task is PROFINET IO communication. The com-
mand message communication is performed as a low priority task. This means that the command
message communication performance is low. Also, the IO Controller can only handle one command
message at a time. Therefore, if multiple devices will address the IO Controller at the same time
over Ethernet UDP, then some of them may not be serviced.
