error message 200016 with USB6259

[spwm]

Hi,

 

I am using USB6259 for motor control. I want to generate PWM control signal using digital output. But the error message 200016 pop up at the beginning of my experiment testing.

 

Measurements: Onboard device memory underflow. Because of system and/or bus-bandwidth limitations, the driver could not write data to the device fast enough to keep up with the device output rate.   

 

Reduce your sample rate, alter the data transfer method (tram interrupts to DMA). Use a product with more onboard memory, or reduce the number of program your computer is executing concurrently.

 

I have questions about this message.

 

1. What does this onboard memory stand for, the memory embedded in USB6259 or the physical memory of computer?
2. I generates the digital pulse. The rate is about 20 pulse/second (these pulse are irregular), and it is far less than the rated 1M labelled in data sheet. Is this phenomena right?
3. What should I do, if I want to reduce the sample rate? I have use DAQmx (sample timing), and I can find any property option can let me reset he sample rate.

 

Has anybody experienced similar issues?

I look forward to hearing any advice.

 

Ben

[Philip.k]

Hey Ben,

The onboard memory is the memory embedded in the USB6259.

I have found a Knowledge Base that produces PWM for a digital output line

for your application 20 Hz seems that it could use software timing.

To increase the frequency beyond 1Hz you must change the representation of Cycle time PWM (seconds)

to a floating point number.

I hope this helps 

Philip

[spwm]

Hi Philip.k,

Thank you for your replay. 

I have two questions. (i) Could you send me a new link of this Knowledge Base ? (ii)The PWM, or I should call it as SPWM, signal is an irregular digital signal. Its frequency changes. It is a comparison results between two signals, the sine signal and the triangle signal. It can be represented as" if the value of sine signal > triangle signal, the out put is "1". Otherwise, the output is "0". I have some progress for just one SPWM. But when I add more (6 SPWM), this error appears and the whole system break off.

best regards,

Ben 

[Philip.k]

Heres the correct link to the Knowledge base. you could using a point by point wave form geniration produce the true false output

If attached a modifed version of the KB code

[Philip.k]

Apology's for forgetting ask but could you send a sample of the DAQmx code that you are using, as when you say that you are writing 6 channels you could be overflowing the onboard Memory due to triggering settings

[spwm]

Philip.k

Thank you for your replay.

This is my program. There are three sets of sine and triangle signal, which represent 3 channels.

The initial setting:               signal          frequency         amplitude

                                          sine                2                       2

                                        triangle            120                    3

I found that the error of 200016 pop up.

If I remove the "case structure" in consumer loop and replace the "DAQmx Timing" with "DAQmx start task. My program can run about 30 second and then the error of 200474 pop up.

My LabVIEW is 8.5, so could you help me converting the "SPWM.vi" to 8.5. Thank you!

Best regards,

Ben 

[Philip.k]

Iv attached the VI for 8.5 I have managed to reproduce the error and belive it is becouse of data type you are writing to the digital output is of the wrong format which im having a look at now.

[lon9horn]

I am happening to a similar problem and hope you guys can help.

I am trying to send 200k points at 500 kHz via a digital output channel.  However, 200016 poped out.

I tried to repeat this with NI MAX, and happened to another error asking for external clock.

In fact, I want to output 6 digital outputs together with 7 analog outputs, among which only the current channel is sampled so high.  However, even reducing the task to a single channel, as mentioned above, 200016 error poped out.