This function return one status line with the current values of the
event counters. The event counters are useful to avoid polling by
delaying a poll until something has changed. The values are decimal
numbers in the range
UINT_MAX and wrapping around to
0. The actual values should not be relied upon; they shall only be used
to detect a change.
The currently defined counters are:
Incremented with any change of any of the other counters.
Incremented for added or removed private keys.
Incremented for each change of the card reader’s status.