DownloadIndustry uses machines that can easily maim or kill their operators and is also used in very adverse environments. In spite of this, production quality must be close to perfect without reliance on operator skill or attentiveness.
Control programs must be robust, yet simple enough to be understood and maintained by non programmer skilled trades like electricians .
The main programming model is the PLC which implements double buffering and an event loop. The most advanced production model relies on smart pallets and autonomous workcells. Each workcell itself will consist of smaller autonomous workcells with very simple signalling used between workcells.
All hardware must extremely robust and well sealed from the surrounding environment.
The webotron project is a program environment which emulates the above for building web scraping tools using temporary Add-on programs running in the Firefox browser. The browser is used to handle all internet interaction and also as a user interface
Features
- Workcells are written as closures with no exported variables or functions
- Programming model is completely parallel using only peer to peer signalling with attached payloads.
- Uses ping-pong synchronization by passing signals from the main event loop to the microtask queue and vice versa.
- Simple programming model because signalling doesn't require an API.
- Workcells are completely autonomous, testing consists only of sending signals in and checking signals sent out.
- Simple interaction with Firefox tabs. A bridge interposer is used between background and content scripts to make a tab and content script into a workcell.
- Currently fully implemented in JavaScript and also in Python https://sourceforge.net/projects/o-scopepy/
- A SEDI.ca insider trading screen has been implemented as a demonstration project