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CTR-502 Frequency measurement in Diadem

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Hi,
 
I´ve tried for a while now to get a correct speed measurement using the CTR-502 Counter module programmed in Diadem DAC.
we got several Field Point systems some years ago, we used to measure speed by measuring time with a hadware interupt and measuring the counts per second.This method gave us a +-20rpm result with which we where ok with.....the problem came when the company decided to change all our computers for new ones, now it is NOT possible to use this interupt and we have to use a software timer instead, this gave us very poor results.
So I started experimenting with other methods and used the one described in the Forums "measuring low frequency in CTR-502" I wrote the program for Diadem (Attachment included) but it seams the counter reset takes to long to activate and suddenly I get a count larger as it actualy is(I am connected to FP through the network). If somebody has an idea of what the problem could be please tell me.
 
My other Idea is to use the time stamp in that case i could know exactly how many count where made in which time even if the info comes a bit later. Does the time stamp come actualy form the Field point hardmare or from the computer? if it does come from the hardware, is it possible to read it in diadem?
 
I may also help to say that our speeds are not larger than 5000rpm (84Hz)
 
thanks for your help
John
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Hello!

Here there is a tutorial for measuring with FP-502.
Using the FP-1600 you can use only method 1:

http://digital.ni.com/public.nsf/websearch/D8DB42F9FDC3607E862568640047F144

Best regards
Ken
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Hello Ken,

Thanks for the reply, but that is the method I tried programming in Diadem and had some problems with the reset, it sometimes takes too long for the command to get to the Field Point through the network and I recieve a wrong value.

Best regards

john

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