What type of hardware are you using? If you open LabVIEW and go to Help >> Find Examples >> Hardware Input/Output, there are many examples on generating pulse trains. You might want to take a look at some of them. Thanks!
I have not come across any example code written for your specific instrument. There is currently a driver for the Ortec 996 (counter/timer) available on our Instrument Driver Network that I suggest you should take a look at. You might be able to use these save VIs with your Ortec 419, otherwise, I would recommend submitting a request for a driver. Thanks!