Fixed Cycle / Canned Cycle
A fixed cycle or canned cycle is a combination of machine moves to perform a particular machining function such as drilling, boring, milling and tapping. Canned cycles the programmer the option to do same routine functions with a simple G-code instead of writing many lines of the program.
If the programmer wants to drill a hole 30 mm deep and clears the chips every 5 mm. Without using a canned cycle, there give would be more than 20 or 30 lines or blocks of program per hole. With a canned cycle, the programmer need to specify the correct G-code for the operation to be performed, add a couple of variables, and then specify the coordinates of the holes.
The machine will drill the desired hole at every defined coordinate Canned cycles are very flexible. Any of the variables/parameters that follow the original G-code can be changed at any time. For example, if we have five holes to drill all of different depths or feed rates we can change the data at any time in the canned cycle.