Need guidance in synchronization

[Hasham622x]

I need guidance in synchronisation in case NI-6255 Mass Termination in which multichannel input signals I am using NI 6255 Mass termination USB in which I planned to use seventeen channels (ai0-ai16) in which channel ai0 will consider as synchronize channel so could you please guide me how should start as I have only one device NI6255.

[GerdW · Accepted solution]

Hi Hasham,

the NI6255 uses a MUX to allow for upto 80 AI channels…

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@Hasham622x wrote:

I planned to use seventeen channels (ai0-ai16) in which channel ai0 will consider as synchronize channel

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So what are your "sync" requirements?

Simple answer: put all channels into one DAQmx task and read "multiple channels multiple samples". The samples will be "in sync" (with respect to MUX switching delays).

[Hasham622x]

Hi,

THanks for your reply ...
I attached VI code with this email which is showing error

please guide how I could solve it

[Hasham622x]

Hi,

I prepared this code for synchronization in which channel ai0 I am using as sync channel and ai1-ai8 as multichannel analog inputs. Sampling rate 1 KHz with continues sampling mode and in data aquisation part I want to catch single peak point of each input channel w.r.t sync channel peak point. Kindly please guide me I need help Please...

[Kevin_Price · Accepted solution]

You need 1 task that includes all channels rather than multiple tasks with 1 channel each.  The AI subsystem has only 1 timing engine available to control sample timing, thus the first task to start gets access and any subsequent ones throw an error.

Run just one task and designate your channels as "Dev1/ai0:1".  Later you can expand this to "Dev1/ai0:16" to accomodate all 17 channels in the same task.

-Kevin P

[Hasham622x]

Thanks for your reply. As I want to delay channel ai0 and then want ai0 as the sync channel, and according to sync channel, ai0 need to note data points from input channels

Kind regards

Ha

[Hasham622x]

and if you dont mind could you please guide me how I could count ai0 channel as sync channel in code by which conditions should be introduced in code ...

[Kevin_Price · Accepted solution]

Sorry, I do not understand what you mean about ai0 being a "sync channel".  What does that mean?   What makes ai0 special in your setup?

-Kevin P

[GerdW]

Hi Hasham,

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@Hasham622x wrote:

I want to delay channel ai0 and then want ai0 as the sync channel, and according to sync channel, ai0 need to note data points from input channels

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Please explain your sentence, best with an image…

• What is "to delay a channel"?
• How is "ai0 as the sync channel"? Sync to what?
• What means "to note data points"?
• What is an "input channel" when you talk about "ai0" aka "analog input 0"?

[Hasham622x]

Thanks for your reply,

I want to use the aio input channel as the SYNC channel and set ai1 to ai8 as input channels. In the data acquisition process, I want to get the peak points of all input channels with respect to the SYNC channel's peak point. I tried to use peakdetector.vi, but I am confused about how to use it.

Could you please guide me on this?