Instruction manual

AMPDIO DRIVERS
Page 164
This second timer/counter may be on the
previous chip.
pper pointer to float: Pointer to a 32-bit floating-
point variable into which the period result will
be placed.
Returns short: OK
or ERRHANDLE
ERRCHAN
ERRRANGE
ERRDATA
Prior Calls registerBoardEx
See Also TCgetExtFreq
6.4.9.2 Measure Frequency of an External Signal — TCgetExtFreq
Returns the frequency of an external signal, in Hertz. The external signal must be connected
to the clock input of the timer specified by the chip and chan arguments. See section 3.1.5 for
more details on the Frequency/Period Measurement application.
i = TCgetExtFreq (h, chip, chan, pfreq)
where h short: board handle as issued by the
registerBoardEx function.
chip short: address offset of the timer/counter chip.
One of the following pre-defined constants may
be used:
X1 = 0
X2 = 4
Y1 = 8
Y2 = 12
Z1 = 16
Z2 = 20
chan short: timer/counter channel number within the
chip (0, 1 or 2). Another timer/counter (chan–2)
will also be used to provide the gate signal.
This second timer/counter may be on the
previous chip.
pfreq pointer to float: Pointer to a 32-bit floating-
point variable into which the frequency result
will be placed.
Returns short: OK
or ERRHANDLE
ERRCHAN
ERRRANGE
ERRDATA
Prior Calls registerBoardEx