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Reading backup status – Rockwell Automation 1769-SDN Compact I/O DeviceNet Scanner Module User Manual User Manual

Page 140

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140

Publication 1769-UM009E-EN-P - August 2009

Appendix B CompactLogix Backup on the DeviceNet Network

Reading Backup Status

You can read the backup status of the DeviceNet scanner module with a single
rung of ladder logic. The backup state is useful for debugging or more
sophisticated backup schemes. The message in this rung uses the SINT data
type.

This figure shows the rung you can use to read the backup state.

This table describes the possible values this message may return when reading
the backup status of the DeviceNet scanner module.

Rung 6 Message Configuration and Communication tabs.

If the message
reads this value

The backup state of the DeviceNet scanner module is

0

No backup scanner module detected

1

Primary scanner module forcing Idle (backup in Run mode but
primary in Idle mode)

3

Primary scanner in Run mode detects backup scanner in Idle mode