vibration controlling with piezoelectric

[chiwa]

Dear All,

I would like controlling vibration at flexible cantilever beam with piezoelectric. I am using PID controller in Labview. I have a problem to generate signal for piezoelectric with DAQ (I am using NI USB-6251), i can not connect DAQ Assistant with PID controller because there is no input data for DAQ Assistant.

 i attach my block diagram so u can at ease understand my problem,

please give me advice,

Thanks,

Nizwa

[RavensFan]

Did you set your DAQ assistant up for an analog output?

If you set it up for an analog output, then the Express VI will have a data input.  If you set it up for an analog input, then the Express VI will have a data output, which is the situation for the VI you circled.

[chiwa]

I set it up for Counter Output, because i want to give frequency signal to Piezoelectric,

[chiwa]

I set it up for Counter Output, because i want to give frequency signal to Piezoelectric,

[RavensFan]

A pulse output task doesn't require any data.  The pulse information (on time, off time, frequency) is all determined by timing settings on the task wire.  Once the timing information is set, there is no other data other than telling the task to run.