Cascade counters on DAQCard 700

[rbaerg]

I am trying to cascade counters on a DAQCard 700 (8253/54) so I can count
events beyond the capacity of one 16-bit counter. I am trying to use the
output
of counter #2 as the clock input of counter #1, in effect constructing a 32
bit
counter. I am running LabVIEW 5.1, which contains the ICTR Control.vi
which
is used to control the 8253/54.

I believe my difficulty must be in the setup mode I am choosing. I have
been
using the control code 4 for the first counter. According to the LabVIEW
documentation,
in setup mode 4, the output is initially high. While the gate input is
high, the counter
counts down. When 0 is reached, the output becomes low for one clock pulse,
and then goes high again. That should provide a pulse to the second c
ounter
which
should then increment each time 0 is reached. I do not seem to be getting
the
output pulse as expected when 0 is reached on the first counter.

Any ideas would be appreciated.

Randy

[Filipe A.]

Randy;

To be able to actually have the output pulse on the output pin of the counter, you need to use one instance of the Route Signal.vi, and have the data source and data signals parameters as the output of the counter. That will route the output of the counter to the output pin of the counter.

Reagrds
Filipe A.
Applications Engineer
National Instruments