Asynchronous Serial Communications Programmer's Reference Manual (32022-90052)

178 Chapter8
Intrinsics Reference
FCONTROL(22)
FCONTROL(22)
Parameters
controlcode 22 — Obtains the time used for completion of the last
read.
param 16-bit unsigned integer by reference
(required)
Returns the measured time duration of the last read in
hundredths of a second.
Notes 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.
Condition Codes
CCE Request granted.
CCG Request granted, but the result overflowed 16 bits (read
took longer than 655.35 seconds).
CCL Request failed because the file number specified did not
belong to this process or the device is not a terminal.
Additional Discussion
See the discussion on “Timing a Read” in Chapter 3, “Common Device
Control Functions,” of this manual.