This object reports on the status of the backplane protocol heartbeat.
This object is applicable only to intelligent MIMs residing in an MMAC
If the heartbeat is detected from the management module (i.e. the
intelligent MIM is in communication with the management module) then
the value returned by this object is heartBeatPresent(1).
If the heartbeat is not present, then the returned value is
On intelligent MIMs that do not support the backplane protocol and
management modules the value notSupported(3) is returned.