Digital Output Trigger

[bmoores]

Hello,

I'm trying to use Matlab to output a combination of analog and digitial signals.  The hardware that I'm using is the PCI-6229 card and a BNC-2110 connector box.  I would like the digital signal to act as a trigger, so it needs to output a TTL level voltage simultaneuously with two analog output channels.  The problem that I'm running into is that I cannot generate a high enough voltage to the digital channel (user-defined signal #1 on the BNC-2110).  On my oscilliscope, the digital signal is usually around 500mV, but I would like atleast a volt.  I'm having this problem when generating the signal with both Measurement & Automation Explorer and the Matlab output.  Is there a way to increase the digital output voltage from the DAQ?

Thanks for the help,
Brad

[Abhinav T]

Brad,

You should be able to output more than 1V as per TTL specs. Have you tested this using Measurement and Automation Explorer's test panel? You will need to configure the digital lines as output lines and set them as high to see 5V as shown in the following picture:

Also, do you see this on all lines on all ports? If this behaviour persists you may have a defective board and you may need to send this in for repair.

Additionally you should be able to use the analog output on your 6229 card to create a signal higher than 1V.

Message Edited by Abhinav T on 07-05-2007 04:43 AM

[rpurser]

Since you're having the same problem in M&A and MATLAB, I'm guessing it's electrical.  If you remove all connections from the board, and put a meter on the DIO line in question, do you see a TTL level output?  If so, then there's something in your electrical connections that's dragging down the output voltage.

-Rob