A quad B signal as trigger for analog daq trigger

[nkang11]

Hi everyone,

I'm trying to use an A quad B signal to trigger my daq device to acquire current input.

The system information is: 32-bit Win XP, NI PCI-6236 counter card.  The A quad B signal is generated by a hardware circuit simulator to work as the output of optical linear scale which is not installed yet.

All I want to do is collecting a current data at certain positions, like 20nm, 40nm, 60nm.... (for example, I use X1 coding, a period of A channel is 20 nm) so that I can plot out the current signal as a function of position. I specified the trigger as uprising.

I'm confused by the mechanism of "Sample Clock" and "Trigger" because they are both physically implemented by the A quad B signal. Am I right? So how to specify the sample mode and sample rate according to the trigger?

I attached the vi here and I can not get any chart plot out. I appreciate that if anyone could give me some hints on it.

Thanks,

Kang

[Esteban_B]

Hi Kang,

It seems that the circuit that you have generates a digital signal; I would suggest you to use this signal as your clock for the analog input.

You can find an example related to this if you open your NI Example Finder and go to: Hardware Input and Output  » DAQmx  » Analog Measurements » Voltage » Cont Acq&Graph Voltage-Ext Clk.vi

You’ll need to wire your digital signal to one of the PFI lines of your device.

Regards,

[nkang11]

Hi Steve,

Thanks for your reply. I tried again. there is always an error 200284 about samples.I checked the hardware, it is connected correctly.

Thanks,

Kang

[Esteban_B]

Hi Kang,

The error that you mention is related to a timeout, I found this article that describes some strategies to solve this issue.

Regards,