LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Triggering using PCI-6233

Solved!
Go to solution

What is the best way to trigger an analog input to start data acquisition when the test unit starts to move?  I am using a PCI-6233 DAQ card.  The input voltage is generated by a linear transducer.

 

Thanks

0 Kudos
Message 1 of 8
(2,783 Views)

Hi,

 

You can use a DAQmx trigger VI. What type of sensor do you have on your test unit that will provide your needed stimulus? Is it a digital signal that will be used as a stimulus or is it an analog signal?  You could look at the example finder to find how to use the DAQmx trigger VI. If you go to the Help link and choose Find Examples, the example finder will appear. In the search tab type in trigger and the first example that comes up should be the Acq&Graph Voltage-Int Clk-HW Trig Restarts.vi. I hope that this helps.

 

Regards,

 

Perry S.

Applications Engineer
National Instruments
0 Kudos
Message 2 of 8
(2,771 Views)

I am currently using an on/off switch to act as my digital trigger stimulus.  I have a 10VDC source wired into my DAQ card at PFI0.  I am using the DAQ assistant to configure my acquisition and have set up the triggering as digital edge/rising.  I would assume that turning the switch on should trigger the DAQ card to start acquiring data, but it doesn't do anything at this point.  The VI times out without acquring any data.

0 Kudos
Message 3 of 8
(2,764 Views)

I have been able to configure the trigger in in the DAQ Assistant.  However, I have been unable to wire the switch to the DAQ card successfully.  How do I physically wire the trigger signal into the DAQ card?  I haven't found anything on the internet or in my DAQ card manual that clearly shows this.

 

Secondly, is there a way to trigger the data acquisition based on this analog signal coming in from my transducer?  For example, could an increase in voltage of the analog signal trigger the acquisition?

0 Kudos
Message 4 of 8
(2,756 Views)

Hi,

 

To connect the DAQ device to the switch you will need to get a  connector block and a cable that runs from the connector block to the device. On the National Instrurments website the recommended connector block to use is CB-37F-HVD and the recommended cable was  SH37F-37M Cable (1m).

 

To answer your second question, you can trigger the data aquisition based on the analog signal comming from a transducer. To set this up in DAQmx task window go to the triggering tab and specify the trigger type as analog edge. Then you would specify the trigger source (voltage), slope (rising)  and level.I have attached a picture for you to see what I am referring to. I hope that this helps.

 

Regards,

 

Perry S.

 


Applications Engineer
National Instruments
0 Kudos
Message 5 of 8
(2,753 Views)

Hello Perry,

 

Please forgive my ignorance on this.  I have the cable and connector block, but am unsure what terminals to hook where on the connector block.  I was running a 10V reference signal to PFI0 from my panel meter, but that didn't seem to trigger the acquisition.  Someone else mentioned that I would need to use the trigger out signal (5V) on my DAQ card to trigger this data aquisition.  I have been through the manual for the PCi-6233 and haven't been able to determine exactly how to wire things up from there.

 

Also, I tried to set up the analog trigger as you have suggested and noticed that my DAQ assistant doesn't give me an analog option (please see attched).  Maybe the PCi-6233 doesn't support analog triggering?

 

I really appreciate your help on this and any additional insight you could give me would be greatly appreciated!

 

Gerry

0 Kudos
Message 6 of 8
(2,746 Views)
Solution
Accepted by topic author gp@CWC

Gerry-

 

Your card doesn't support analog input triggering.  Your card should support a digital signal of 10 VDC, but if you are worried about the voltage being to high to cause it to trigger, then you could use a voltage divider to reduce the voltage of your trigger.  You might try falling edge in case your switch is wired backwards.

 

If the signal you are measuring is a floating source and you are using differential measurement, you would hook the positive lead to terminal 1 of your connection block and the negative lead to terminal 2, and use a jumper wire between terminals 2 and 3.  This is the best way to measure a floating source.

 

If the signal is floating and you're not really worried about introducing ground loops, you could hook it up as reference single ended.  That is, the positive lead goes into terminal 1 and the negative lead goes into terminal 3.

 

You would use these same to setups if the source is grounded.  Again, differential is the best setup for avoiding ground loops.

 

For your trigger, you would attach the positive lead from the 10 VDC source to terminal 13 and the negative lead to terminal 14.

 

I hope this helps!

 

Thanks,

 

Sean  

Applications Engineering Specialist - Semiconductor Test
National Instruments
Message 7 of 8
(2,729 Views)

Thanks so much Sean.  This helps greatly.

 

Gerry

0 Kudos
Message 8 of 8
(2,725 Views)