TL;DR - is a RPI 3B (64bit processor at 1.2 ghz, ~950mb of ram) capable of running Mango successfully with the data rate that I need?
Hey all, I just wanted to give my perspective on the use of a Raspberry Pi 3B and my attempts to use it as a light weight, low power, all ways on SCADA. I tried out Mango about 4 years ago and was hoping to use it to form the base of a new supervisory system for a couple of distilleries.
First of all let my preface this by saying that this SCADA platform would be very very minimal in terms of C. All controls are handled by embedded PLC's and PACs and this was to be almost exclusively for Data acquisition and visualization. One of the distilleries is running experiments and being able to view 15-20 temperature sensors at a given time and have them graphing every 1-5 seconds is imperative.
I originally had some issues with installing Mango that was largely unrelated to the RPI so I'll not go into them other than TL; DR - it's possible to have an imported user profile get messed up. Delete it an make a new user.
Installation went fine. About 40 points were loaded (about 300 eventually) and at most 21 are viewed at a given time. For my tests I didn't bother making custom pages, just stuck with the watch lists. After running from anywhere from 10 minutes to 10 hours, the memory usage of Mango would rise to a terminal level and I'd have to kill process because commands would no longer work.
The next fix was to move the Mango install off of the memory card and onto an external USB drive. This went fine and re-importing all the points went just fine, but the same memory error persisted (not all that surprisingly). I enabled memory_small.sh and set the java memory a couple of ways. I even moved all of the RPI's physical memory that was devoted to the GPU over.
The result was the same, the memory usage start spiking, CPU hits 100% and then I have to kill the process. Next attempt at a fix was to make a nice big, juicy swap disk but that didn't do anything either.
I'm not a java expert but I'm really surprised to see how much this spikes considering that visualization should be happening client side. All administration of this board is being done remotely via SSH and VNC with Mango being viewed on intranet and externally via VPN. Network connections aren't factors here.
So here's my question - is a RPI 3B (64bit processor at 1.2 ghz, ~950mb of ram) capable of running Mango successfully with the data rate that I need. Right now my answerer seems to be no, but maybe someone else see's a glaring hole in my process or has been successful with this board.
Also, running the exact same points on a core i5 with 8gb of ram and an SSD (yes I know, a gun to a knife fight) does not even remotely replicate the issues above. The idea of having to run a relatively high powered box 24/7 kinda defeats the purpose.