About bostroemc

bostroemc · ‎12-02-2020

A simple Python app that accesses the data layer via the REST API is available here: https://github.com/bostroemc/webconnector-lite The app polls a (fixed) PLC variable, then pushes the value out a WebSocket where it may be read by a web page. (A sample html page with the required WebSocket client is included.) To build the app for the ARM-based ctrlX CORE, I used the build tool supplied by Canonical: https://snapcraft.io/ Note that the PLC variable TYPE is not fixed, and may be any simple type (DINT, REAL, etc.) or even an array of these simple types. Until Python is fully supported by the SDK, access via the REST API might be a good option for some applications. (Note that this sample app is fully self-contained does not require that the "Python app" be installed on the CORE.)

bostroemc · ‎11-09-2020

The variant class includes some helpful conversion operators. In the SDK (1.5.0), see include/comm.datalayer/comm/datalayer/variant.h. I was able to read PLC variable Position (defined as REAL), using the following: result = client->readSync(temp, &value); float f = float(value); (In your case, with Position defined as LREAL, you'll need to use double, but the principle should be the same...)

bostroemc · ‎10-08-2020

As a suplement to the official "how-to" mentioned by CodeShepherd, see attached. Some write (PUSH, PUT) examples are included.

bostroemc · ‎09-03-2020

I updated my snapcraft.yaml file so that the application would be installed as a service. The revised file is shown below with changes highlighted: Complete working project is attached.

bostroemc · ‎08-21-2020

I have a simple Python application that serves a WebSocket. I succeeded in snapping the application and running it on Ubuntu 18.04.5 LTS. I'm also able to install the snap on virtual ctrlX CORE (1.4.1). However, when I try to run my snap (server-alt) on virtual ctrlX CORE I get the permission denial shown below: How do I point my snap to the writable snap folder (presumably this is /writable/system-data/snap/server-alt), as opposed to the default (and in our case non-existent) snap path: /home/$USER/snap/server-alt? Complete project together with sample html is attached.

About bostroemc

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Running snap on virtual ctrlX CORE