ABB AC 800M

Configuring LD 800DN Linking Device Unit Section 4 Configuration
120 9ARD000014-600 A
LD 800DN Timing Parameters
A direct correlation exists between the following LD 800DN timing parameters:
• Foreground to Background Poll Ratio.
• Inter Scan Delay and their corresponding Expected Packet Rate value.
The following conditions need to be satisfied for a successful communication in
DeviceNet devices:
• If the Strobe connection is enabled or the Polled connection is enabled with
Poll Type set as Poll Every Scan Cycle, then
((Inter Scan Delay) <= (Expected Packet Rate))
• If the Polled connection is enabled with Poll Type set as Poll At Background
Rate, then
((Foreground to Background Poll Ratio * Inter Scan
Delay) <= (Expected Packet Rate)
The Control Builder checks the above correlation between the parameters based on
the connections enabled on the DeviceNet devices. The download is aborted with an
error message if the conditions are not satisfied.