06-06-2007 07:40 PM
06-07-2007 06:47 PM
Hi TJW,
In order to start two tasks simultaneously, we will want to set the arm trigger. An example of this, although more complicated than you
need, is Meas Angular Position-Buffered-Cont-Ext Clk-Arm Start Trig.vi (Help
>> Find Examples… >> Hardware Input and Output >> NI-DAQmx
>> Counter Measurements >> Position). This is a good example of how
to start multiple tasks together, along with assigning the property nodes for
the arm trigger.
06-09-2007 01:54 PM
06-10-2007 02:10 PM
06-10-2007 10:18 PM - edited 06-10-2007 10:18 PM
Hi TJW,
The reason you are getting the DAQmx timing error is because performing 'period' and 'two edge separation' counter tasks both require either 'Implicit' or 'On-Demand' timing, not 'sample clock'. Attached is the example program, modified so that both counter tasks use implicit timing, along with the 'arm start trigger', assuring that the tasks will both start at the same time when the trigger occurs. Also, the picture below helps explain what clock mode is used for each type of trigger task. (see picture and details at bottom of picture) This information can be found in the NI-DAQmx help (Start >> Programs >> National Instruments >> NI-DAQ), following the tree seen in the left-hand side of the picture.
Message Edited by David L. on 06-10-2007 10:20 PM