PLC controller can load and run small binary programs (PLC procedures). PLC procedure should be wrirtten by simplified C-like language, compiled and stored in PLC controller memory to be ready to go.
PLC Builder - tiny IDE (Integrated Development Environment) to create and modify PLC procedure source files, compile them to binary code and upload it as RomFS iso image disk to PLC controller memory.
To open PLC Builder goto
PLC Builder IDE Widget
PLC Builder Screen Components