Voltage of the counter output is low

[lyzhab]

Hello,

I am using a PCIE-6353 DAQ. I tried to use an oscilloscope to measure the voltage output of a counter from the MAX and my labview code. I found it is only about 0-2.6V. I wonder if there are any software methods (like some specific property nodes) to increase this clock output to trigger other devices.

BTW, I attached an image of parts of my code, where I used the digital input to detect both the rising and falling edges of an external trigger signal and then use the ctr0 to generate a clock with the double frequency. The new generated clock is almost synchronized with the orginal trigger (200 ns delay). But if I insert an Implicit (Finite Samples, 1 sample) between the CO Pulse Freq and Start Digital Edge, there was a sinificant delay. So now I need to delete it. When I should use the Implicit? Also, if I used an oscillioscope (500MS/s) to detect the Dev1/PFI0, which was generated from the Export Signal VI, I found the amplitude of the short pulse trains seemed very unstable although the output from the ctr0(PFI12) seemed stable. Is there any way to increase the amplitude and pulse width of the output pulses of Dev1/PFI0?

Thanks a lot!

[crossrulz]

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@lyzhab wrote:

I am using a PCIE-6353 DAQ. I tried to use an oscilloscope to measure the voltage output of a counter from the MAX and my labview code. I found it is only about 0-2.6V.

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What impedence do you have the oscilloscope set up for?  Make sure that is set to the 1MOhm setting.

What else do you have this counter connected to?  This is typically a current limit issue.  The digital lines are limited to 24mA.  At 2.6V, this comes out to around 100 Ohms.

[lyzhab]

Hello, thanks for your suggestions. I will double check the oscilloscope. The counter is also connected to a Alazar digitizer as a trigger input.

[lyzhab]

Hello, if I just use the oscilloscope with 1MOhm to measure the output clock, it is 0-5V although there are some sharp peaks at the edges. If I also connect it to the trigger input of a Alazar digitizer, the measurement from the oscilloscope becomes 0-2.5V. Maybe you are right, it just a current problem. I think the impedence of the digitizer is 50Ohm though. But anyway, if I only plug this counter output to the digitizer (no oscilloscope), then it should be fine, right?

[crossrulz]

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@lyzhab wrote:

I think the impedence of the digitizer is 50Ohm though. But anyway, if I only plug this counter output to the digitizer (no oscilloscope), then it should be fine, right?

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The 50 Ohm from the digitizer will also be a problem.  You will want an op-amp or some kind of digital line buffer that can give you more current output if you really need the 5V at the digitizer.