Doing Buffered Event count by using Count Buffered Edges.vi, what is the max buffer size allowed?

[lyn]

I'm currently using Count Buffered Edges.vi to do Buffered Event count with the following settings,

Source : Internal timebase, 100Khz, 10usec for each count
gate : use the function generator to send in a 50Hz signal(for testing purpose only). Period of 0.02sec


the max internal buffer size that i can allocate is only about 100~300. Whenever i change both the internal buffer size and counts to read to a higher value, this vi don't seem to function well. I need to have a buffer size of at least 2000.


1. is it possible to have a buffer size of 2000? what is the problem causing the wrong counter value?


2. also note that the size of max internal buffer varies w
ith the frequency of signal sent to the gate, why is this so? eg: buffer size get smaller as frequency decrease.


3. i'll get funny response and counter value when both the internal buffer size and counts to read are not set to the same. Why is this so? is it a must to set both value the same?

thks and best regards
lyn

[RamziH]

Hi,

I have tried the same example, and used a 100Hz signal on the gate. I increased the buffer size to 2000 and I did not get any errors. The buffer size does not get smaller when increasing the frequency of the gate signal; simply, the number of counts gets smaller when the gate frequency becomes larger. The buffer size must be able to contain the number of counts you want to read, otherwise, the VI might not function correctly.

Regards,
RamziH.

[lyn]

thks ramzih,
why is it that the number of counts get smaller when the gate frequency becomes larger? and what does you mean by "the buffer size must be able to contain the number of count you want to read"

i noted that the vi does not function correctly when the count to read was increased too high. why is this so?? what can i do to sovle this problem?

thks,lyn