beremiz

SVGHMI: JsonTable now use intermediate variables again to address JSON data without duplicating code or referencing. Using intermediate variables also alows to check for availability of data and stop evaluating early if data is missing. Finally added complete roundtrip example to illustrate use of JSonTable to display "alarms" collected in python from changes on PLC boolean variables.
Project overview
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In order to target the widest possible range of programmable devices and keep efficient, Beremiz use C code as an intermediate language.
To be executed, C needs to be compiled. `GCC <http://gcc.gnu.org>`_ serve that purpose perfectly.
PLC program is expressed in languages defined in IEC-61131, including graphical languages. Thanks to PLCopen TC2, those graphical languages have a standardised representation, in XML.
To be continued.