Hi Anne,
I noticed that you are using software timers in your program. Do you want to use software timers or do you want to use your hardware counters (PCI-6602) as timers?
The best way to get started with counters is through the shipping examples in LabVIEW 7.0. You can get to your specific examples for your counter board in LabVIEW by selecting Help >> Find Examples >> Hardware Input and Output >> Traditional DAQ >> Counters >> NI-TIO. In this directory, you will find many examples with using counters. Experimenting with the basic counter types in this directory will give you a good idea of how to use counters for more complex tasks.
Hope that helps. Have a good day.
Ron