e-HMI and nginx webserver possibilities

PLCnext Technology & PLCnext Controls
1

Hello everyone,

I have been working on showing historical data, from a external database, in a graph or table with PLCnext hardware. Even tough you can do many things with the different HMI features, I couldn’t quite achieve the result I was looking for with the e-hmi. So I turned my attention to adding a raw HTML page (with Chart.js for example) by using the support files function in PLCnext Engineer. I looked into the REST API for getting data to my chart, but realised this data (coming from a external database) needs to be present in the GDS to use it with the REST API. I dont think storing huge amount of data from a database in the GDS is how the GDS is meant to be used.
I dont know enough about HMTL, JavaScript, and Webservers to figure out the correct way to do this, if there even is a correct way of doing this. So I was hoping if people on this forum had any idea’s or tips to achieving my goal of showing histrorical data, from a external database, in a graph with PLCnext hardware.

2

Hello!
For now it is very pure compatibility for data visualization in eHMI itself.
I think that your task in general could be covered with join of MySQL as DB storage (Use DBFL SQL* from PLCNextStore to read and write DB directly from PLC) and Grafana as pretty web-based dashboard manager. DB server and Grafana both can be launched on your developer machine or operator PC, or some other specially dedicated machine in the network. Also, there is Grafana image specially adapted to PLCNext platform on PLCNext store…
On eHMI page you have to provide link to configured Grafana dashboard.
Basic settings of this components are well documented, so you can get involved fast enough.
Best regards.