Hello
I want to read a digital signal from a custom build high resolution spectrometer.
Each spectrum is composed of 2000 channels * 12bits.
Each channel information is sent one after the other on a 12-wire bus every 6.25 us.
Two more wires are used:
- One for the channel clock (every 6.25 us (160 kHz))
- One for the spectrum clock (approx. every 2000 * 6.25 us = 15 ms (70Hz))
I am using a M-Serie 6224 DAQ board with Labview 7.0 and DAQ-mx 7.3.
I wired
-the 12 bits D0-D11 on the port0/line0:11
-the channel clock to pfi0 (port1/line0)
-the spectrum clock to pfi1 (port1/line1)
Now, in the vi,
what i wanted to do is to use the channel clock (pfi0) as an input for the sample clock to read the digital inputs.
This works fine. I can get my information, but not synchronized on the beginning of the spectrum.
The other thing that i wanted to do, is to use the spectrum clock (pfi1) as an input for the digital trigger in order to start reading the data each time there is a falling edge on this input (begining of the spectrum).
But as soon as i plugged the DAQ-mx trigger vi, even if it is set to input:none, there's an error:
Error -200452
Specified property is not supported by the device or is not applicable to the task.
Start.TrigType
But, the DAQ-mx trigger vi works fine when input task is analog
So now my questions are:
Is it possible that M-serie boards cannot read digital port when an external trigger is used??
If yes, where is my mistake ?
Otherwise, are there any workarounds ??
I hope I was clear enough so that someone can help me.
Thanks
