User manual

DeviceNet 5-3

I/O Message Types

The BridgeWay supports all I/O messaging types specified by the DeviceNet pro-

tocol. These include strobe, poll, COS, COS Unacknowledged, Cyclic, and Cyclic

Unacknowledged I/O messages. I/O messaging and I/O parameters are configured

using the DeviceNet configuration tool.

I/O Mapping

The contents and layout of the data in the I/O tables is defined during configura-

tion of the scan list. The input and output data of each slave is configured, or

mapped, to specific locations in the input and output tables.

I/O Table Byte Swapping

The BridgeWay provides an I/O byte swapping option. If the option is enabled,

the data in the I/O tables is byte swapped on 16-bit boundaries. This is very useful

if the Ethernet protocol being used is Modbus/TCP since Modbus assumes the

byte ordering is opposite of that of DeviceNet.

Do not enable byte swapping if the Ethernet protocol being used is EtherNet/IP.

Input Data Safe State

The BridgeWay provides the option of configuring how the DeviceNet input data

will be set when a DeviceNet slave connection faults. The safe state behavior

may be configured as either “Maintain Last State” or “Zero Data”. If the option is

set to Maintain Last State, the input data associated with a DeviceNet slave will be

frozen to the last value received from the slave prior to the connection fault. If the

option is set to Zero Data, the input data associated with the slave will be set to 0

when the connection is faulted. Only the input data associated with the particular

slave’s I/O mapping configuration will be affected, all other non-faulted slaves’

data will continue to update normally. Note that this is a global setting and all

slave connections will be treated in the same manner.