how to synchronize SERIAL PORT and USB-6229

[LV_Enthu]

do i require any additional hardware to get this sync done between serial port(usb-serial port) and usb-6229?

[Albert.Geven]

what do you want to synchronise?

what is coming from serial, what is coming from usb?

what time resolution do you need (seconds or microseconds)?

[LV_Enthu]

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@Albert Geven wrote:

what do you want to synchronise?

what is coming from serial, what is coming from usb?

what time resolution do you need (seconds or microseconds)?

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i would like to save data from DAQmx from USB-6229 and some serial data(volts) from usb-serial converter(com port basically) into 1 file. the serial data is coming at 9600 baud(fixed).

i wuld like to save this data in hh:mm:ss.x format.

[Albert.Geven]

You did not answer how accurate your synchronisation needs to be

[LV_Enthu]

i did not understand what do you mean by how accurate?i would like to save every sample being collected, does it answer your question?

[Henrik_Volkers]

So we know you have a USB 6229...

so, whats on the rs232? a $20 cheapo DMM with a 1S/s output or Agilent ??? with serial out and soft/hard-trigger??

What do you mean by synchronize? 

If you record every second will a mismatch of +-1s between the capture times of the different instruments hurt?

How do you collect the data frm the 6229? Do you use triggers?

Without a hardware sync you have to count with a random mismatch due to the OS .. coarse guess 20ms but will that matter?

[LV_Enthu]

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@Henrik Volkers wrote:

So we know you have a USB 6229...

so, whats on the rs232? a $20 cheapo DMM with a 1S/s output or Agilent ??? with serial out and soft/hard-trigger??

--- i have voltage signal coming from USB-SERIAL convertor, i dunt know what is the input to that USB-SERIAL converter.. is it another DAQ, or an electronic circuit dunno...

What do you mean by synchronize? 

-- by synchronize, i mean that when i save the data coming from two DAQ systems, they should be stored in a file without any loss of data. Since the clock on these 2 DAQs are independent, and of different values, there is a possibility that 1 DAQ has some data at a given instance, while other DAQ does not (just because their clocks and rate of acquisiton is different), so, i would like my system to either coerce or have a common clock base, so that I can cut out this problem.

If you record every second will a mismatch of +-1s between the capture times of the different instruments hurt?

Yes,,, it will because in that case, I will have 100% error? Will I or I am wrong?

How do you collect the data frm the 6229? Do you use triggers?

No, I have generated a simple task using the internal clocks of the CPU. no triggers nothing.. i used Daqmx Start Task.vi

Without a hardware sync you have to count with a random mismatch due to the OS .. coarse guess 20ms but will that matter?

 i have no clue about it... did not try yet

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[Dennis_Knutson]

When you find out what make and model of instrument is going to be used, post back. Otherwise, speculating is just a complete waste of time.

[Henrik_Volkers]

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@Dennis Knutson wrote:

When you find out what make and model of instrument is going to be used, post back. Otherwise, speculating is just a complete waste of time.

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Maybe he can help: 😉

[LV_Enthu]

hello all,

           i found out something on the hardware from which the serial data is coming in... its basically a DAQ box which would simulate the DAQ boxes from NI. it is built up of all board level electronics, Filters, Amplifiers, micro-processor, etc... i found that the max baud rate is 115k on that electronics box....

does this help?