how do i synchronize AO, AI, and GPIB?

[lucretius]

I am using an e-series board, with LabVIEW 5.1, in which both of the counters are used to ramp two separate voltage supplies. I am acquiring data through an SCXI module and from an electrometer. The frequencies of interest are 0.2 Hz and 0.5 Hz. Is there a way to output the scan rate as a pulse train even though both counters are in use? I should mention that the trigger on the electometer needs a TTL pulse, at least 10 microseconds wide. I've tried using FREQ_OUT (it's too fast), and SCANCLK (the pulse width is too narrow). Any help would be appreciated.
Thanks

[Raecine Meza]

The pin you are interested in is called STARTSCAN, and it shares the same pin number as PFI7. When this pin is configured as an output, it pulses at the start of each new Analog Input scan operation. I don't have any specs on the pulse width of the signal.

To make sure the PFI7 pin is being used as an output, use the Route Signal.vi with PFI7 as the Signal Name and AI Scan Start as the Signal Source.