Rockwell Automation 1788-EN2DN Ethernet-to-DeviceNet Linking Device - Manual (Page 27)

Ethernet-to-DeviceNet Linking Device 27
Rockwell Automation Publication 1788-IN055C-EN-P - September 2011
(Optional) Configure DeviceNet I/O
I/O Mapping
The DeviceNet I/O configuration defines the format of the Input and Output
tables, or the mapping of DeviceNet slaves’ I/O data to the I/O tables. As slaves
are added to the linking device’s DeviceNet scanner configuration, the location
in the I/O tables of each part of the slave’s I/O data is determined and stored.
To configure DeviceNet I/O, use RSNetWorx for DeviceNet software to set the
linking device’s scan list and I/O table mapping.
IMPORTANT Steps 8 and 9 are required only if the linking device is used as an I/O scanner.
The linking device can function as a gateway/bridge, even if no I/O is
configured.
IMPORTANT The organization of the I/O tables is very important. I/O tables define the
format of the data that will be provided to the EtherNet/IP scanner. The Input
and Output table formats should be planned and documented to be sure the
EtherNet/IP scanner is working with the correct data from the DeviceNet
network.
The size of the I/O data that can be exchanged with the EtherNet/IP scanner
(and, hence, the size of the I/O tables) is restricted as explained below.
• The Input table size cannot be larger than 496 bytes.
• The Output table size cannot be larger than 492 bytes.
• Either table may be empty (0 bytes).
IMPORTANT Automap is used in this example for simplicity. In some cases, you may want
to organize the I/O data in other ways; you can do this using the Advanced
data table editor in the Input and Output tabs. Refer to RSNetWorx online
help for complete details.