The operate station is used for operating the proces, a graphics terminal if you will.
The process system is only controlling the system.
They can be both the same physical system but they can also be separate systems.
A raspberry Pi 3 is in my experience to this day capable of being a server, process and operator station in one.

I've spent last couple of weeks a lot (too much? ) time on setting up and creating a stable runtime and development environment.
My tips:

-Just like marc said, a fast desktop environment for development makes you happy:D. I've set up a Ubuntu 16.04 LTS i386 environment on VirtualBox. The i386 version makes some things work easier out of the box (java etc)

-I use the raspbian stretch lite as base for the process station

-If you want to use data history server on the rpi, use sqlite on the raspberry instead of mysql. It takes less resources

-Had a lot of issues with corrupted memory cards. My solution was to put the proview files (the /pwrp map) on a usb stick. Next step for me is creating a readonly mmc environment with only data being written to usb stick

-starting proview on a process station with rt_ini -i can give you a lot of useful information

-Systemd does some weird stuff when ssh-ing and starting and stopping things. My solution
sudo loginctl enable-linger pwrp
and in /etc/systemd/login.conf
KillUserProcesses=no

Yes ok...

So for now i have a usdt form desktop for the development eviroment.
Goal is to have the pi control the operating and process control in one.
In combination with a touch schreen for the HMI.

Thanks for the programming tips...not there yet, but i keep thrm in mind.
Good idee to keep the data storage separately...if i,m on that page i'll ask you how to

For now i,m waiting for the dallas temp sensors first thing to make them work with readout and everything.
And the installation of the proview and making the operating display with the readout of the dallas temp sensors.
Then going to think about a pid controller software for the heater...


So still lots of research to do for this newby programmer

Now i'm starting up but i can not save my project.

But i'm not getting forward.

I'm logged in in Linux as my onw user
If i start proview it's logging in as pwrp

but i keep getting no write access, as the att file shows, what am i doing wrong?

What what are the permissions of /usr/local/pwrp ?

/Marc

owner = root (read write)

groep= pwrp (read write)

others= use files

Are you sure?

A directory needs an executable bit.

$ ls -ld /usr/local/pwrp
drwxrwxr-x 8 root pwrp 4096 Feb 6 12:08 /usr/local/pwrp

/Marc