ABB AC 800M, Configuration

Page: 182 / 260

Scan Cycle Section 6 Linking Device LD 800DN
182 9ARD000014-600 A
Scan Cycle
The Scan cycle of the linking device is used for its communication with DeviceNet
slaves. A scan cycle consists of the following:
• A Strobed Message and associated Strobed responses.
• Polled messages and responses.
• Inter scan delay, which is the time delay between consecutive I/O scans.
Setting Inter Scan Delay to a very low value increases the latency for non-time-
critical operations. Setting this parameter to a very large value reduces the
newness of the I/O data being collected by the linking device and is not advisable.
Figure 69 shows a graphical illustration of the Scan cycles.
Inter Scan Delay is used for performing non-time-critical operations, like
configuration using explicit messages.
Figure 69. Scan Cycles