[OT] 2D real-time chart for VB6

[kender]

Colleagues,

In your travels, have you seen a good chart control for VB6 that can make a real-time 2D plot?

I need to plot a signal on the screen in real time. The update rate of the chart will be on the order of 200ms to 1000ms, and I want to display around 1000 points. Ideally, the whole chart would scroll to the left as new values are added on the right (like a strip chart).

I’ve tried the MSChart, it looks OK, but it wasn’t written as real-time chart. MSChart flickers on every update, and there’s no way to get rid of flickering. Flickering is a real problem, because somebody will be staring at the chart for hours.

Thanks, and have a happy new year!

- Nick
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Read the label, before opening a can of worms.

[Guest]

I really like Gigasoft PreEssentials - nice professional looking plots / Not that un-Excel / Power-pointless look, but a good solid engineering look.

Free unlimited demo too.

HTH - Steve H.

[Guest]

Oops - can't type - should be PRO Essentials!

[ELCouz]

Try RRDTool very powerful !! http://oss.oetiker.ch/rrdtool/gallery/index.en.html

I have integrated in many apps both Delphi and C++

Very good for long time plotting and fast too ,, take 5 minutes to generate a 10 years plot with more than 1 million data points :P

I can render in real time depend on your configuration not sure you can do RT with more than 10000 points per refresh with a less than 500mhz pc.

EDIT: 1000 ms is good , but you need a good computer to render in less than 100 ms

[kender]

I ended up going with the RMChart control. It's very powerful, it has good sample projects for VB6, it has a support forum, and it's free.

http://www.rmchart.com

-Nick
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Read the label, before opening a can of worms.

[Neutone]

TeeChart is a good product.
http://www.steema.com/
It might be out of your budget but its fast and it has a lot of features. They have a trial version you can look at to see if it will meet your needs. I have used it to display strip charts with 8 signals updated at 50-100mS intervals with no problem. That was 5 years ago using VB6 and a 1GhZ machine.

[Ttelmah]

I do this with TChart.

However one 'critical' thing is to change the way the chart is drawn.
If you add points at the right hand edge of the chart, then every time a point is added, the whole chart has to shift left. Even with a fast machine and video card, a huge amount of redrawing.
I display my chart typically with 35 minutes visible, with 5 minute axis ticks along the bottom, and start drawing one tick left of the right margin. When I reach the margin, I move the chart left five minutes as a single move, and carry on. This gives a single chart update every five minutes, rather than every time a point is added. So the line is growing across the last five minutes all the time.
I have zoom functionality (to allow individual points to be accessed), and 'hover' to get the value at a point. Zoom levels are 35mins, 5mins, 1min.
If you go off the left edge of the chart, the previous half hour is loaded. Back for up to 24hours.
'home' takes you back to the current chart.
For me, there are 8400 points across the chart (35 minutes, 250mSec/value), with the updates being done in the last 1200 points.

[Zloi]

little out of context,
Did you consider using Labview for general programming and displaying charts ?