waveform chart or graph?

[steffi.kono]

Hi everybody:

I receive data (values and time stamp) via TCP/IP, which I'd like to display on a waveform chart/graph. Right now I bundle the values with the time stamps and display them on a graph, but I have two problems: First of all I like to scroll the display so that it doesn't become confusing and I think I can't do it with the graph, do I? Do I have to take a chart for this option? Where is the difference? And how can I create a chart with the time values?
Secondly I would like to display the time at the x-scale in the following way: hh:mm:ss:ttt, where ttt stands for milliseconds. My timestamp from the TCP/IP looks the following way: dd:mm:yyyy hh:mm:ss:ttt , so it shouldn't be that complicated, but I don't know how to solve this. So far I bundled the values of the timestamp and used the "Date/Time To Seconds.vi", but I don't like that solution as it becomes a huge number...

Maybe anyone can help me out? I only have LV 7, just in case...

Thank you very much in advance!
Steffi

[waldemar.hersacher]

Steffi,

are the values evenly on the time axis, meaning is deltaT the same between each value?

In this case you can convert each set of values you receive into a waveform. You can now wire the waveform to the chart.

Difference between chart and graph:

The chart has a databuffer for some values called the history length. You add the waveform to the end of the databuffer and this will be displayed. The old data is moving to the left. This way you can scroll within the data which is in the buffer.

The graph doesn't have a databuffer. The waveform will be displayed at one curve. If you need to add new values to the curve you need to add them to your old waveform and write it again.

You use a chart for online display and a graph for offline analysis.

The Date/Time to Seconds function is right to convert your time. Make a mouse right click on the x-Axis of the chart or graph. In the submenu use "Formatting..." and choose  "Absolut Time" and display only the time without the date.

[steffi.kono]

Hi Waldemar,

thank you very much for your help.
Yes, the delt T is the same between each value.
I will try your sugestions next week, thank you!

Steffi

[waldemar.hersacher]

Steffi,

this will match because I'm out of office for the rest of the week too.

[steffi.kono]

Hi Waldemar,

which vi did you mean exactly by "convert each set of values into a waveform"? Should I take the "Build Waveform.vi" with my first time value as T0 and the timer of the while loop as dT? Or is there another solution so that I can take my values and the corresponding time stamps?

Thanks,
Steffi

[waldemar.hersacher]

Yes Steffi that's the VI. T0 is the timeof the first sample and dT is your acquisition period. If you have a software timed acquisition it is the timer of the while loop.