Internet PLC Forum

General => Technical support => Topic started by: CMS on March 26, 2007, 10:02:43 PM

Title: PWM measuring accuracy
Post by: CMS on March 26, 2007, 10:02:43 PM

If I have a PWM input at 500hz into one of the HSC inputs, what sort of accuracy will I get in measuring the Duty cycle?

Many Thanks

CMS

Title: Re:PWM measuring accuracy
Post by: support on March 26, 2007, 10:22:16 PM

Don't use HSC, use PMON inputs and you can measure down to 1 microsecond resolution the pulse width and pulse period, then multiply the 100 and divide pulsewith by pulse period to obtain % duty cycle with 1% resolution. If you pre-multiply by 100000 then you can get duty cycle between 0.000 to 100.000%, i.e. 0.001% resolution.

Title: Re:PWM measuring accuracy
Post by: CMS on March 26, 2007, 10:30:15 PM

Thanks once again for your support

Much appreciated