frequency measurment

[Moran]

Hello,

I am new in plc and visilogic and i need some help,

I need to measure the frequency of a square wave , I tried to use HSC Frequency Measurement FB , but it does not work.

( my square wave freq is slow... about 2Hz)

I connected my signal to I0 of a V200.

Can someone please tell me what should I do to measure the freq of that signal?

Do you have any example?

I am using V570 and V200-18-E2b

By the way:

My square wave should be 24v?

Thanks,

Moran.

[Emil]

Hi Moran,

Attached is a working example with frequency measurement function. I hope it will be helpful.

Frequency-precise meter.vlp

[Gabriel Franco]

You can also use Hardware Configuration, setting high speed input as HSC and frequency measurement linked to an MI or ML. It will give you Hz directly, however its resolution is just 1 Hz.

You must check your wiring as well.

[Moran]

hi ,

thanks for your replies,

i will try your solutions,

gabriel, my square wave signal must be 24v? to the I0 of the V200?

[Emil]

Hi,

Yes, the signal needs ot be 24VDC. It can be PNP or NPN.

The way of Gabriel is easier, but gives resolution of 1 Hz. "My way" gives resolution and precision of 0.01Hz, but needs reading Help topic and probably example to implement it.