Hello Peter,
I'm not sure exactly which of the following situations you're asking about, but both have fairly straight forward answers.
If you want to use a TTL trigger to start an analog acquisition then you can just configure your analog input task to use a digital start trigger. You can route this trigger into the PCI-6259 via a PFI line. As soon as you call the DAQmx Start Task VI the task will wait for a rising edge on that line. For an example of how to do this go to the LabVIEW Example Finder (Open LabVIEW and go to Help» Find Examples...) Then navigate to Hardware Input and Output» DAQmx» Analog Measurements» Voltage» Acq&Graph Voltage-Int Clk-Dig Start.vi. This example configures the trigger acquisition I described above.
Option two is that you want to start an analog acquisition and at the same time output a digital signal on a PFI line to send from the PCI-6259 to your function generator. If this is the case, there is an internally generated digital edge whenever you start your task. You can use the DAQmx Export Signal VI to route the DevX/ai/starttrigger to a PFI line of your choice. This will generate a rising edge whenever you start the analog input task.
I hope this helps and have a great day!
Brooks
