Software suppliers can give you a good solution to your needs based on their own experience. The point is that you can not have control of the software more than choosing PLC hardware, SCADA vendor or IO list. Know How protection is a common response for source code requirements.
There are not open standards that go beyond IEC 61131 PLC programming languages.
Many things are kept open like:
- Variable naming.
- I/O Assignation.
- Max Routine length.
- Block Interdependency.
The software developer employs spreadsheets to witch you don’t have access.
Software blocks are made with limitations like a recipe with limited number of elements, once you ask for extension the price is unaceptable.
You can request these things in your specification, but you fear that this will make the code even worse as the supplier will try to comply literally and will charge you additionally.
You just dream in an open software standard made to make life easier to plant operators, not to feed someone else business.
Elimar.com is the effort of a former plant engineer to develop such a solution.