National Instruments FP-CTR-502 Operating Instructions Manual page 16

To determine the frequency of the output from the pulse counter,
use the following formula:
where f
pulse
f is the prescaler counter output frequency
pre
term
Step 3. Configure the Pulse Train Output Channel
To configure the pulse train output channel, complete the following
steps:
1. For the output channel that you selected, set the Output Source
to the pulse-counter channel.
2. Set the Output Mode of the output channel. To generate a pulse
train with variable duty cycle, use one of the pulse modes—On
Pulse or Off Pulse. To generate a 50% duty-cycle pulse train,
use one of the toggle modes.
To determine the duty cycle, use the following formulas:
For On Pulse mode, use
For Off Pulse mode, use
where d is the duty cycle of the pulse train
term
When you set the output to one of the pulse modes, the frequency
of the pulse train (f
the Pulse Counter
you set the output channel to one of the toggle modes.
© National Instruments Corp.
f =
pulse
is the pulse counter output frequency
is the terminal count value for the pulse counter
pulse
d =
d = 1 –
is the terminal count value of the pulse counter
pulse
) is the same as that shown in
pulse
, but the output frequency is half that value when
f
pre
--------------------------------
term +
pulse
1
--------------------------------
term +
1
pulse

1
--------------------------------

term +
pulse
15
1


1
Step 2. Set Up
FP-CTR-502 and cFP-CTR-502