Select this item to instruct the software to poll the enclosure status information via the disk drives which are capable of communicating with it. In the event of a problem, messages will be reported per settings in the Rulesets.
Most SES enclosures (which are applicable to fibre channel hosts only) allow two or more devices to communicate with the enclosure services processor. Because SMARTMon communicates with the enclosure through disk drives mounted in it, then the same problem would ordinarily be reported for each disk drive in the enclosure.
SMARTMon is aware of this, and will only report the same problem once. It does so by remembering the unique world-wide-name associated with each controller, and once an error message is reported for it, the program suppresses duplicate messages.
If your enclosures have a SCSI host attachment, then they don't use SES, they use SAF-TE. SAF-TE is also an ANSI-defined standard for enclosures. It differs in that SES communicates with a controller via a disk drive mounted in the enclosure. That is, SMARTMon selects a device, then sends pass-through SES commands to it which are then returned by the disk drive.
In SAF-TE enclosures, there are one or more dedicated service processors that appear as a special device type (3) that is specifically designed for SAF-TE queries. The bit map that looks like a disk array with a red light identifies a SAF-TE service processor. The image around a disk drive with the SES text indicates that the disk is one of the designated SES devices which can communicate with the array.
This link will show you a sample of some of the reportable information on a specific enclosure.
Note that unless this feature is enabled, SMARTMon will not send additional I/Os necessary to determine whether or not a specific device is in a SES enclosure, and capable of communicating with it. It will, however display SAF-TE devices as SAF-TE devices (see the icon above) as this is a simple operation and does not require additional I/O.