ProSoft Technology AN-X-MOD - Manual (Page 53)

AN-X-MOD (Master) Page 49
when you add elements, the offsets in the comments generated by the
autoconfiguration will no longer be correct.
Make sure the mappings in the ControlLogix configurations in both
AN-X modules are the same. Each AN-X module cannot check the
configuration in the other AN-X module.
LEDs
When the AN-X-MOD (Master) is used in redundant mode, the network
LED is green when scanning, orange when monitoring and red when
there has been an error or during switchover.