A constant number decremented by count programming problem

[fhaertlein]

Here's the problem......

I have a constant number, say, 9987009745.

This number needs to be decremented by a counter. The pulses input to the counter vary from 0 to 2200 Hz. I need to count these pulses and deduct the pulse count once each second from the constant number.

This is part of a "totalizer". In other words 1 gallon of fuel flow is equal to 1875 pulses. The input frequency can vary from 0 to 2200Hz as the fuel flow increases or decreases. Each pulse needs to be counted and subtracted from the constant number and then the result displayed.

Can somone help me program Labview to do this? I'm learning so only have an evaluation version of Labview.

Thanks in advance.

[Burt_S]

Hello, I think the best place to start with this would be to ask what hardware you are using.  If you are using hardware that has its own counter, then you can simply take your constant value and subtract the value your hardware counter returns.  If you don't have hardware with its own counter, the problem becomes much more difficult.  Assuming you are using hardware from NI, that has its own built in counter, you can take a look at the counter examples in the example finder and start from there.  Also, here is a good getting started course to help with the learning process.  I hope this helps!

http://zone.ni.com/devzone/cda/tut/p/id/5243