Showing results for 
Search instead for 
Did you mean: 

Error -805 due to timed loop missing proper timing source

I have a Async. custom device that was designed with a timed-loop. It's rate must be 5kHz, so dt = 250usec.


How can I set the timed loop to operate at this rate, since the custom device is developped under Windows, and the timed loop highest rate is 1 khz? 


When  get error -805 when undeploying the device, and at runtime the timed loop never runs.




0 Kudos
Message 1 of 6

There is only a 1kHz SW timing source available on windows, as opposed to the 1MHz timing source available on RT. You can, however, use hardware timing to drive a timed loop past 1kHz on windows. The most direct way is using a DAQ card and the DAQmx driver to create a timing source from an acquisition task or a digital change event. Refer here for some more details. There are also examples available in the Example Finder.

Jarrod S.
National Instruments
0 Kudos
Message 2 of 6

Ok, but in the context of a Veristand Custom Device that will run on the Target, I need to use the 1 MHz clock.  I need to get this timed loop run at 250us. What is the name of the clock I should use?



0 Kudos
Message 3 of 6

The way to do what I mean should be  like this: 


- add a RT target under the Custom Device Project

- drag the RT Driver VI under the RT target and set the Timed loop at 1 MHz.

- bring the RT Driver VI back under Windows

- Do NOT open the propertie of the timed loop.

- reset the RT Driver VI in the build as mentioned here



0 Kudos
Message 4 of 6
there is a vi in the structures -> timing palette to create a timing source. 1kHz or 1 MHz selectable.
Stephen B
0 Kudos
Message 5 of 6

What Stephen mentioned will work. Also note that 5kHz = 200usec, not 250.

Jarrod S.
National Instruments
0 Kudos
Message 6 of 6