Canned cycle (Fixed cycle):
It is defined as a set of instructions, inbuilt or stored in the system memory, to perform a fixed sequence of operations.
[1] It reduces programming time and effort.
[2] Canned cycle is used for repetitive and commonly used machining operations.
[3] To save the repetition of programming of common operations, the cycle is used called affixed cycle/canned cycle.
[4] The sequence of standard cycle of operation is stored in the memory of the computer.
[5] When that information is required at the time of machining is activated from memory, by using proper G–code.
[6] One of the most frequently used canned cycles is the drilling cycles.
Subroutines:
Subroutine called, subprogrammes, are a powerful time saving technique. It provides the capability of programming certain fixed sequence or frequently repeated operations.
These are independent programs with all the operations of a usual part program.
[1] Subroutines are stored in the memory under separate program numbers.
[2] When particular operation is required in the program, the associated subroutine is called for completing the operation.
[3] Subroutine also called as sub programs.
[4] After completion of subroutine the control returns to main program.