User manual

DeviceNet 5-7

Interaction with I/O Tables

The DeviceNet interface in the BridgeWay accesses the I/O tables as slave I/O

connections are processed by the DeviceNet master; there is no buffering or timed

updates of the I/O within the module. Safeguards are in place to ensure data integ-

rity by prohibiting simultaneous access by the Ethernet and DeviceNet interfaces.

There is no synchronization between the 2 network interfaces.

When an I/O connection with a slave requires that output data be sent to the slave,

it will be read from the Output table. The data read is what was placed there by the

last write to the Output table by the Ethernet interface. Transmission of data on

Change of State (COS) connections is triggered when new output data is provided

by the Ethernet interface in the region mapped by the connection.

When input data is received on a slave’s I/O connection, it is copied to the Input

table. This data is available to be read by the Ethernet interface and sent to the

EtherNet/IP scanner on the next data exchange.