measuring pule width

[Moran]

hellow,

i need to measure the width of 1 squre pulse . this pulse is 50ms and about 20V amplitude ( which i have to measure ).

i am using V570 and V200, i thought using the V200 digital input and start timer , and when the pulse is at low state stop the timer.

can i do that? how?

if someone has a better idea i will be happy to hear.

thanks,

Moran

[HigHTech]

I think you can use a HSC and use the frequency option. Then you can calculate the width.

[Joe Tauser]

If it's only one pulse you won't be able to measure the frequency - the HSC input averages the pulse counts over a period settable from 100 ms to 1s. As soon as your pulse is gone the frequency register will reset itself back to zero.

A timer won't work well for this; the best resolution you can get is +/- 10 ms plus the scan time which is typically 3 -10 milliseconds (depending on your program size).

Read the Help on the 1.25 ms interrupt routine and set it up to to use an immediate input to increment a counter as long as the pulse is high. The routine solves every 1.25 ms, so you move the count value to another MI when the input goes low. Then it's a matter of multiplying this count by 1.25 to get the pulse width in milliseconds.

Joe T.

[Moran]

hi,

thanks for ypur reply,

i did use the interrupt routine, the 2.5ms routine and it is working, i am incrementing a counter and multiplying by 2.5.

thank you..

Moran