Shared sample clock PCI-6052E

[fr123]

Hello,

I downloaded this vi "Multi-Function-Synch AI-AO-Same Clock.vi". It seems I can use it to do what I want but I have some questions regarding is operation.

1- The PCI-6052E board have a sample rate of 333kS/s. If I try to set the Input/Output rate to 100kS/s (This should work because, 2x100kS/s=200kS/s<300kS/s), I get this message "Error -200279 occurred at DAQmx Read (Analog Wfm 1Chan NSamp).vi:1". I also tried to reduce the sample to read to increase the loop velocity but I still get this message. Could you explain me what append?

2- I want to modified the vi "Multi-Function-Synch AI-AO-Same Clock.vi" to generate a pulse waveform of N finite samples and read the data with "number of samples per channel" equal to -1 which mean the VI (DAQmx Read.vi) waits for the task to acquire all requested samples, then reads those samples. What append to my data if the input buffer size of the PCI-6052E is 512 Samples and I want to read a waveform of N>512 Samples? In other hand, If I used a while loop to run DAQmx Read with a finite number of sample to acquire (e.g. x<512<N), how can I determine x to be sure that I am at the maximum sample rate of the board (i.e. 333kS/s divided by 2channels = 166.5kS/s) and that the loop is fast enough to read all the data?

3- If I want to add an other AI (AI_2) synchronized with the existing AI (AI_1) and AO (AO_1), can I used the same sample clock as AI_1 to be sure that all the generated-acquired signals is performed at the same time? What is the maximum sampling rate that I can use per channel (333kS/s divided by 3??)?

Thank you for your help

[Lars M]

Hi,

reffering to question 3:
                                        All cards of E and M Serie have a multiplexer on board
                                        which switches the channels to the AD converter. So you are right, the maximum
                                        sample Rate you can use for each channel is the maximum rate of the device divided by the number
                                        of used channels. Yes you can use the same sample clock for more channels.

reffering to question 2:
                                        to detect the maximum sample rate use a DAQmx Timing Property node change to write
                                        and select the property "sample clock" -> "maximum rate"

reffering to question 1:
                                        the error  -200279  demonstrate,that the values the program wants to read got
                                        overwritten. Solution : increase the buffer size at the DAQmx timing VI (connect a constant to the input
                                        "samples per channel") For the detailed error description see the following links ->

                                        (DAQmx) Error -200279 During a Continuous, Buffered Acquisition
                                        http://digital.ni.com/public.nsf/allkb/7AD4854943BF344186256D6500807935?OpenDocument

                                        Common NI-DAQmx Error Codes and Solutions: Codes -200000 to -200299 and -50103
                                        http://digital.ni.com/public.nsf/websearch/001DA4DB6A31CF8886256D33006FA857?OpenDocument#200279

Hope this will help you

Best regards

Lars

[fr123]

Hi Lars,

Thank you for these precisions. My application is almost finish but I still have problem to write synchronously 2 AI with one AO. I get Error -89131 occurred at DAQmx Start Task.vi:3 when I try to run it.

Maybe you have an idea of what is wrong

Here is my code

Thank you again

[Lars M]

Hi

The following link will help you to understand.

Why do I Get an Error When Selecting "/Devn/di/SampleClock" as my Sample Clock Source on my M-Series Hardware?
http://digital.ni.com/public.nsf/allkb/DE1F365AEE0FDDE386256F40005C44FE?OpenDocument 

Lars