Charting Process Data
Hi,
I've been able to create a small application the PLC next to display the process data on the web based HMI. The tools have been quite straight forward to use and setup. However, I did not see a way to graph or chart the process data with respect to time? I saw in the forums mention of data logging (2019.6), Proficloud and Graphana, but my application will be offline (no Proficloud) and other solutions seem a bit complicated for a simple web chart for plotting data over time. Is there a simple way to chart data on the web HMI?
Thanks,
Comments
Hello bhelfrick ,
there is currently no predefined symbol for this usecase.
The question is how many data you would want to display and how fast you want to refresh ect.
You could build a shift register for data + timestamps and add fixed amount of registers to a symbolist of some bargraph symobl you design.
Or you create a HTML5 page and use JavaScript to implement a dynamic chart.
There you could also embedd a eHMI page to add some buttons or something similar.
Hi Oliver,
Thanks for the quick response.
These are both good ideas. I think the second option would provide the best flexibility.
From a brief review of the documentation, it looks like I can install something like Chart.js. Would this be a correct assumption?
Hey,
yes you can provide "support files" to the ehmi.
Those will be downloaded with the application.
And you can link from a ehmi page to a support file you created. (with some button)
(Or you directly acces it like this 192.168.123.123/ehmi/SomeSupportfile.html)
Which is then in turn using the chart.js to display data.
To fill it with data you will need to use the REST Api in that case.
To get data from the PLC to the client viewing the Page.
Something like this:
https://github.com/PLCnext/HTML5_with_REST