S71200 HSC Pulse/Sec to Pulses/Hr

[EITechbenny]

Hello,

can anyone tell me if it possible to infer an intermediate speed measurement from a frequency measurement in pulses per second.

i.e. I have a HSC that counts in Hz such as 15Hz......16Hz.......17Hz.......18Hz.....etc
I would like to be able to get intermediate measurements such as
15.3Hz.....16.25Hz......17.8Hz......18.6Hz......etc

is this possible to do this with a High Speed Counter. I have the HSC configured on a Siemens S71200 PLC

regards

 

[controlsdude]

the subject is different than what you asking.

if you program for the rising and falling edge of the signal you could get double the input hz.

If you go the opposite in time then your just a straight conversion by counting the pulses for per hour.

 

[EITechbenny]

Thanks for the reply

But if i configure for a pulse for every falling and rising edge am i not miss interrupting a pulse? is that the "A&B Quadrature"? i hear this term before?

I don't understand what you mean when you say

"If you go the opposite in time then your just a straight conversion by counting the pulses for per hour."



Well what i mean by pulses per sec to pulses per hour is that i have a HSC measuring pulses per second and am converting this figure to pulses per hour by multiplying the per/sec value by 3600. the problem is that a jump from for example 15 pulses per sec to 16 pulses per sec causes an increment of 3600 (as expected). I would like there to be a possibility of reducing this large step increase by being able to count for example 15.45 pulse/sec X 3600

 

[RajeevCell]

Your problem is you are sampling for 1 second only, and then extrapolating the result for 1 hour. Large steps are inevitable. Why don't you express the speed in "per second" rate, instead of "per hour"? Or you can sample over a longer period.

 

[EITechbenny]

then maximum i can average over with a frequency configuration is 1 sec. i could set up a normal count value and time it. I need the accuracy to be good and it is required that the value is in pulses per hour instantanous value

I thought a HSC would measure frequency with intermediate values such as 15.3.....15.5....15.9Hz....etc?