How can I make a rolling display / use a graph widget?

Discuss issues and ideas you have to configuring displays with PowerVision
normanbutchgrant
Posts: 25
Joined: Fri Oct 28, 2016 9:07 am

How can I make a rolling display / use a graph widget?

Post by normanbutchgrant » Thu Apr 20, 2017 10:22 am

Hi, all.

I am trying to create a display with a datalogger for a vehicle fuel consumption test.

The test will be done on a oval track where the driver has no obstructions and the requirement is to match speed over time, and be repeatable.

A key function required for this is to display (for a driver) a drive cycle which s/he should follow and repeat for the tests, human error being accounted for by various methods. We intend to do this comparison every second and inform the driver how well he has met the requirement and whether to accelerate more or less.

The drive cycles are typically 1300+ lines (of CSV of time versus speed), which are already coded and displaying on a gauge or bar graph. This works just fine, with feedback from current speed to show a +2km/h or -2km/h "demand" to show how close the driver is to matching the cycle. (This is done in a set of scripts to remove the need for a single huge table.)

However the driver does not know what is coming next in the cycle so it makes it difficult to follow the drive cycle, beyond "go faster" and "go slower".

What would make the tests more repeatable is a graph display (or two overlayed graphs) to see current time +10 and -10. This is to see history and expected future demands on the one graph, and the current ("achieved") speed on another graph.

I saw the "graph widget", but could not understand how to get my data in to a "list" and "column" format. Is the graph widget the correct tool for this application? If not, which tools can be used to show history and future required speeds?

I can provide the *.CSV/*.TXT to show the drive cycles (all available online) should they be needed.

Regards,
NormanButchGrant
boyce
Enovation Controls Development
Enovation Controls Development
Posts: 322
Joined: Wed Sep 08, 2010 5:09 pm

Re: How can I make a rolling display / use a graph widget?

Post by boyce » Fri Apr 21, 2017 11:02 am

It sounds like the graph widget is the right control to use. Like you said, you could use 2 graphs to show the current lap and the upcoming target values. The sample configuration List and Graph Demo shows how to use a list to hold the data for the graph widget and an activity program to add rows to the list on a timer. The current list would add new data and move the graph to the end (ListMoveLast) like the demo. The history/target data could be in the list and the graph just move along (ListMoveNext). The hard part might be getting the history data into a list. It can be done by using a script with the history data in arrays. There are ListManagerImport and Export but that data would be stored on a USB stick. There should be a way to do it, it will just take some work.
Boyce Schrack
Enovation Controls
normanbutchgrant
Posts: 25
Joined: Fri Oct 28, 2016 9:07 am

Re: How can I make a rolling display / use a graph widget?

Post by normanbutchgrant » Mon May 01, 2017 2:09 pm

Hi

We did as described and it is working

Thank you once again

Norman