Rockwell Automation 1761-NET-DNI DeviceNet Interface (DNI) - Manual (Page 45)

Publication 1761-UM005B-EN-P - October 2006
DNI Configuration Parameters and Programming Notes 45
Data Scan Delay
When Data Enable (parameter 3) is enabled (DNI Series A) or I/O
Scan Enable (parameter 12) is enabled (DNI Series B), the value
entered for Data Scan Delay defines the amount of time that the DNI
will delay between communications. This value does not identify how
often communications take place; it defines the delay between the
completion (end) of one communication sequence and the beginning
of the next.
See the application example MicroLogix as I/O on the DeviceNet
Network on page 69 for more information about using the Data Scan
Delay.
Data Scan Delay Parameter Definition
Parameter
Type Parameter Number Description Range Default
Value
Series A Series B
I/O 13 14 Data Scan
Delay
(Polling Delay) 20…3000 ms 50 ms
IMPORTANT
It is important not to set this value too low. Setting
Data Scan Delay too low limits access to the
controller from other devices on the network. If this
value is too low, programming terminals, other
controllers, and any other devices attempting to
communicate with this controller are unable to due
so, because the RS-232 port communications link
bandwidth is being consumed by the I/O scan
feature of the DNI.
IMPORTANT
To move data from the controller to the DeviceNet
master as quickly as possible, use the DNI’s input
messaging feature.
See input messaging on page 49.