XY Buffer for 2 points

[Grass_Pitch]

I am trying to plot two counter vales (acquired one point at a time from a DAQ card). Using a single XY-Buffer works well, but I cannot seem to show both counters in a single plot. Can someone tell me how I solve this problem.

On the same question, is there any advantage in using a XY buffer over a (shift-register + Build Array) combination.

A screen shot of what works and what does not is shown below.

[altenbach]

I guess it all depends what's inside the xy-buffer subVI. 😉

I cannot find this VI in my 7.1 distribution. Is this something that you made or downloaded from somewhere?

[Grass_Pitch]

It is avaliable under 7.0

Select a Vi (in function palette) -> Go to Labview 7.0 Examples-> General -> Graphs-> Charts-> XY Buffer.vi

[altenbach]

OK, found it.

The xy-buffer is not intended to buffer multiple plots, just multiple points for a single plot. The array input is used if there are multiple points added at once to a single plot.

What you need to do is buffer each plot separately, then build the array for the multi-plot using "build cluster array". See e.g. XY-Chart C or D in the quoted example.

The XY-buffer is reentrant, thus can be used multiple times, each with its own data.

[Grass_Pitch]

Thanks, Altenbach. That (using Build Cluster Array whose inputs are the o/p of the buffers for single plots) solved the problem.