pulse width measurement for dummies

[BenGilbert]

Hello,
I  wish to do a pulse width measurement but I am unable to do so.  I have a PCI-6259 DAQ.  I am using counter 0.

In the current scenario I have a device connected to the gate terminal of the DAQ counter (PFI 9 for the PCI-6259).  When I send a command to this device via a RS-232 it will output a pulse of approximately 100us.  I wish to do a measurement of this pulse.  There are no other connections between the counter and this device other than ground. 

When I run the example vi "Meas Pulse Width.vi" I get an error:

Error - 200474 occurred at DAQmx Read
(Counter DBL 1 Chan 1 Saml).vi:2

Possible reason(s):
Measurements: Specified operation did not complete, because the specified timeout expired.

Task name: _unnamedTask<0>

I assume that this means that it did not find any rising or falling edges in the specified timeout (20secs).  I know that a pulse has occured as I can measure it on an oscilloscope.

What have not done in my setup to make this measurement work?  I am sure it is really simple.

Thanks,

Ben

[Kallis]

Hi Ben,

Have you verified the following.

1. The ground of the device is connected to the PCI 6259's DGND.

2. The pulse that is being generated is of TTL level.

[BenGilbert]

That's it!  There was an electrical disconnection between the counter and the device.

Thanks heaps,

Ben