Hey Archie,
Before I start I'd just like to point out this isn't an idea for logging data so much, I can write the code to log data to a database but what I'm looking for is more of a visual instrument.
I'm attaching with this a photo of a chart recorder from an EZ HMI panel that graphs lines of your setpoints and actual process values in real time.
My idea for you was to make a control that is a graph that the user has properties for a Time span and then also a property of how many increments to break that timespan into on the graph. Also properties for the left side of the graph such as your actual process value like 0 to 2500 degrees etc., and options to set a certain color line to a specific tag your polling information from. Now im not interested in keeping this information, it would just be a nice troubleshooting tool to be able to see what my process values have been for the last hour prior to me being called out to that machine, So what I'm saying is a scrolling graph that once the oldest information has past it is lost. I'd try to make this control myself but I know nothing of how to use graphics in Vb.net.
It be pretty cool if this control is possible to make without logging data but I'm not sure if it is, What do you think?