Instruction manual

AMPDIO DRIVERS
Page 167
Prior Calls registerBoardEx
See Also TCdivideFreq
6.4.9.5 Divide an External Frequency — TCdivideFreq
Measures an external signal’s frequency, then generates another signal whose frequency is
the external frequency divided by a specified number. N.B. this function is not on-going, and
must be called at a regular interval to keep the generated frequency tracking the external
signal. Note the output signal will be a square wave.
i = TCdivideFreq (h, ipChip, ipChan, opChip, opChan, divisor)
where h short: board handle as issued by the
registerBoardEx function.
ipChip short: address offset of the timer/counter chip
on which the input frequency will be measured.
One of the following pre-defined constants may
be used:
X1 = 0
X2 = 4
Y1 = 8
Y2 = 12
Z1 = 16
Z2 = 20
ipChan short: input timer/counter channel number
within the chip on which to perform the
frequency measurement (0, 1 or 2). Another
timer/counter (ipChan–2) will also be used to
provide the gate signal. This may be on the
previous chip.
opChip short: address offset of the timer/counter chip
on which to generate the output frequency.
One of the following pre-defined constants may
be used:
X1 = 0
X2 = 4
Y1 = 8
Y2 = 12
Z1 = 16
Z2 = 20
opChan short: output timer/counter channel number
within the chip (0, 1 or 2).
divisor float: division factor.
Returns short: OK
or ERRHANDLE
ERRCHAN
ERRDATA