Rockwell Automation 1761-NET-DNI DeviceNet Interface (DNI) - Manual (Page 46)

Publication 1761-UM005B-EN-P - October 2006
46 DNI Configuration Parameters and Programming Notes
Message Timeout
The Message Timeout is the amount of time that a DeviceNet explicit
connection is held open after message completion. The Message
Timeout allows the DNI to hold open a connection with another
device over the DeviceNet network. On a DeviceNet network, a
connection means that two devices have established a
communications path. Each time communications need to occur
between devices, a connection is established; when the
communications have completed, the connection is released.
The number of connections that each device can support depends on
the design/capabilities of each device. The DNI has five connections
available for messaging. The Message Timeout allows the user to tune
how a connection behaves after communications have completed.
You may want to dedicate a connection to a specific node/device to
maintain a connection. This reduces the amount of time needed to
re-establish communications with the device.
It is recommended that this value only be changed (from the default)
if communications with another node is constant. When the timeout is
set, the connection is not released back to the system until the timeout
expires (where 0 ms means close immediately after use).
Message Timeout Parameter Definition
Parameter
Type Parameter Number Description Range Default
Value
Series A Series B
Messaging 2 15 Message Timeout 0…2500 ms 0 MS
IMPORTANT
An open connection between devices over
DeviceNet does not limit or inhibit communications
over the network. If two devices maintain a
connection, other devices continue to communicate.