create multiple counter channels

[John2772]

I had a USB 6353 DAQ board, which has 4 counters.  I want use these 4 counters to output 4 pulse trains at different frequncy, duty cycle with different delay.

I am using Microsoft visual Studio 2019 and tried NI's .Net example code.  The example code uses only one single counter.  When I tried to "create" another counter, it report error.

Here is my code,  

coTask = new Task();
dioTask = new Task();
coTask.COChannels.CreatePulseChannelFrequency("Dev1/ctr1", "PulseTrain", COPulseFrequencyUnits.Hertz, COPulseIdleState.Low, 0.0, 1000, 0.5);

--------- the ctr1 counter is created without error 

//The following line  report error when create the second counter channel "Dec1/ctr0

coTask.COChannels.CreatePulseChannelFrequency("Dev1/ctr0", "PulseTrain",COPulseFrequencyUnits.Hertz, COPulseIdleState.High, 0.0, 100, 0.3);
------ it report, "Specified channel cann't be added to the task, because a channel with the same name is already in the task"

If I only use one single channel,  Dev/ctr0 or Dev/ctr1, my code works.  Where I did wrong? I need to create a task for each counter to use "createPulseChannelFrequency()" function? or there are other functions to use all counters?

[santo_13]

You'll have to create a separate task for each counter.

Depending on the type of pulse generation, more than one counter may be required for a task, please refer to this article - https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P7eESAS&l=en-US

[John2772]

Thanks, Santo_13