Help needed....How to read an output signal of the integrator into the labview after the HOLD signal turns OFF.

[srinathv]

hello Everyone

I am working with an ACF2101 IC, I gave a hold and reset signal from the labview scb-68 connector board through the counter. Basically this is what i have done.

Step 1: I have put a DAQ assistant on the block diagram and configured it to the 2 counters which are available on the connector board and thru that were able to give digital pulses which trigger the hold and reset of an integrator.

The question is:

How am I able to read the integrated signal from the output of the IC for a period of 200us just after the HOLD signal turns low (switch is open), should READ for 200us before RESET signal turns ON, this is a very narrow window.

I tried to explain the problem to my best, if you have any questions regarding the clarity, please email me back

your help is highly appreciated.

thanks
sri

[Joe_H]

What type of data acquisition card are you using that is connected to the connector block.

[srinathv]

I am using an NI-PCI 6281 ,its an M-series DAQ BOARD.

[srinathv]

I am able to read the signal into the labview from the output of an IC, but have to read it only for a brief period of time,  for 200microsec, just after the start of  trailing edge of one of the Input signals.

[Matt_A]

Hello Sri,

It sounds like you are trying to use a digital start trigger to acquire for a specified period of time. By your statement about using the DAQ Assistant, I am assuming you are using LabVIEW with NI-DAQmx for your acquisition. Is this correct? I have several follow-up questions that will help determine the best method for you to proceed:

1. Are you using LabVIEW? If so, what version?

2. Are you using DAQmx? If so, what version?

3. What type of signal are you trying to acquire? Analog? Digital? Voltage? What frequency is the signal? What range?

All these questions will help you determine the best way to move forward. If you would like to view some options, there are several examples of using triggering available in the LabVIEW example finder. To access this application you can go to the Help menu in LabVIEW and select the “Find Examples …” option. From there I would recommend that you navigate to Hardware Input and Output>>DAQmx. Then select the type of acquisition you are trying to perform. Once you have determined the type of signal you are acquiring, you can look for any example with the phrase “Trig” in the title for an example of how to trigger you acquisition.

I hope this helps. Let me know if there’s anything else I can do to help.

[srinathv]

Hello Matt
 
I have put a DAQ Assistant VI and changed the attributes in it to act as counters to generate digital pulses to be given as an input to an IC, unto there its fine.

The question is if I put one more DAQ assistant and configure it to analog input in the block diagram to read the signal from the IC  and this read should be triggered on the trailing edge of one of the digital signal . The trigger for the read has to start on the trailing edge and read the data into the input read channel for 300 microseconds.
How should I do the above said thing?

The answer for your questions:
 I am using LV8.2 SOFTWARE
NI DAQMX 8.X
TRYING TO ACQUIRE AN INTEGRATED VOLTAGE SIGNAL, BASICALLY A VOLTAGE SIGNAL

I need more direction into this, so can eventually solve my problem.

thanks

Sri

[Joe_H]

Have a look at the example called Acq&Graph Voltage-int Clk-HW trig Restarts.vi 

Change the start trigger to digital edge or give it a digital pattern and see if this will help you.