A call to FCONTROL with a controlcode
of 22 allows you to read the result of the read duration timer for
the last read. The value is returned to your program in hundredths
of a second, up to the 16-bit maximum limit of 655.35 seconds.
Since every read is timed on MPE/iX systems, you should be
sure your call to this intrinsic follows immediately after the read
you want timed with no subsequent reads in between.
FCONTROL(22) should not be confused with FCONTROL(4), which
is a read timeout. FCONTROL(22) reports the length of time it took
to satisfy a read request, after the read completes. No other action
is taken as a direct result of this call.
If this FCONTROL call is issued against a terminal connected
via Telnet/iX or VT, the call will return a CCE condition code but
no device control action will take place. Any value returned in
this call may not be a true reflection of device control settings.