Error - 200077 at DAQmx Timing - Sample Clock with digital out

[imf]

I am using an M sereis card and the SCXI - 1001 with a feed through module (SCXI 1167). When I create a task to manipulate on digital line and wire in the DAQmx Timing vi set to the Sample Clock SampTimingType I get Error 200077 that looks like such:

Error -200077 occurred at Property Node DAQmx Timing (arg 1) in DAQmx Timing (Sample Clock).vi->Cont Write Dig Port-Ext Clk.vi

Possible reason(s):

Requested value is not a supported value for this property.

Property: SampTimingType
You Have Requested: Sample Clock
You Can Select: On Demand

Task Name: _unnamedTask<25>

I cannot even select On Demand as an option.

[Salvador_Santolucito]

Hi imf,

I gathered from the error message that you are using the Cont Write Dig Port-Ext Clk.vi example. This example is meant to be used with the digital IO boards, not the multifunction DAQ boards.

For digital IO you should use the Write Dig Port.vi example program. This program will allow you to write to yoru digital port. You don't need to worry about sample timing because this example uses "programmed IO" which means that the update rate of the digital port is software timed. As you can see from the example the speed that the loop iterates will determine how fast the digital port is updated. This is how all E-series boards work. M-series boards can also work this way.

The M-series boards also have the added feature of correlated digital IO. You can take an existing clock signal (analog inoput sample clock, timebase, external PFI line) and route it as the digital output clock. This will allow you to do hardware timed digital IO. I have attatched an example of this.

Please let me know if you have any further questions.

-Sal