Unique objects know where they are. Software interlocks prevent accidents for example prevent the robot placing an object where there already is one. You can also program intelligent decisions about objects, for example a different path if holding a certain object, or a different location of objects of a certain type. The code is short, concise and efficient. The amount of memory used is amazingly small.
Objects also prevent collisions and mistakes.
Commands to turn the gun or tool on or off may be inserted in the list. Continuous paths are run by the DSP in the controller and programming may be such that the CPU is able to carry out other tasks while the DSP is running the robot. The CPU program can stop the DSP motion prematurely. Inputs may be checked immediately and outputs manipulated directly on a single bit basis. Such commands leave the states of other output bits unchanged by simulating a communication register.