From OpenSCADAWiki
Due the build system BuildRoot was changed for OpenWrt and mostly in the packages description and the feeds repositories appending the build rules of OpenSCADA needed and were fully rewritten and you can download their pack from here and unpack it to folder "package". For build OpenSCADA and its IPKG package from prepared and ready for its BuildRoot folder of the SDK with OpenSCADA rules in the folder "package" you must follow next instruction:
# Clean the package building, at first time you can omit the command
make package/openscada/clean
# Download and prepare OpenSCADA source archive, the commands call automatically at the next command "compile" then can be omited also
make package/openscada/download
make package/openscada/prepare
# Compile OpenSCADA, all dependent packages of the OpenSCADA building at the time and before must be downloaded and compiled automatically
make package/openscada/compile
# Install and build the IPKG package, which you can find here "bin/{paltform}/packages/base"
make package/openscada/install