Basically, the eval_frame function looks at the current bytecode in an execution context, and switches control out to a function appropriate for implementing that bytecode.

All kinds of function modules of pneumatic balance circuits have been designed such as air press regulation, loads switch, execution control, decompression protection and residual pressure exhaust.

Slave computers have data detection and control function with the help of the data capture and control interfaces which are composed of all kinds of position switches, sensors and execution units.