read TTL signal and send the same/modified TTL signal

[sdkpark]

hey guys,

I have a TTL signal being generated from a device, I need my daq to read that TTL signal frequency and send the same TTL signal with DOUBLE the frequency.

the catch is, I only have on available counter i/o left (because the other is being used to generate to power the device).

also have a SCB 68 and I'm reading that the digital inputs can read TTL signals. So will it be possible for the digital i/o to read the TTL signal frequency and output (via counter i/o) the same TTL signal (where I can use LabVIEW  to modify the frequency)?

thanks in advance!

devices:

SCB-68 E series

DAQ PCI-6229

Message Edited by sdkpark on 10-07-2009 07:04 PM

Message Edited by sdkpark on 10-07-2009 07:06 PM

[A_Person]

You can use a digital input to calculate a frequency,  it just won't be as easy as with a counter as you will have to do it in software.  At that point, you can set a frequency on the counter output. 

The other problem with using the digital line is that it cannot read as high of a frequency as a counter can.  What frequency are you expecting your signal to be?  That will help determine how feasible this setup is for you.

[sdkpark]

my highest frequency (F) will probably not go higher than 50 Hz.

ugh i have no idea how to set up the method you suggested to do so lol

thanks for the response!

[A_Person]

With that low of a frequency you would be fine using the digital lines for either input or output and using the counter for the other.  I will try to post an example of this later.

[sdkpark]

here is what i have so far actually (in picture attached)

for some reason it only outputs on the first line of digital output

maybe it's because of the error daisy chain and everything goes in series?

i'm going to try to make it independent by making it separate and will tell you how it goes later today.

also this is the original example i got it from.

it's actually different from what i am asking but generally it is sending out 3 different frequencies (F, F/2, and F/4) in SYNC (using the same internal clock).

thanks in advance!