In the next stage, the same example will be explored
-step or derly
pro ce dure for any op er a tion or ac tiv ity (only a very ge neric model is pre sented here):
1 Start program
Initialization – defaults – cancellations – units,
2 Input data
Tool – spindle – location – clearances,
3 Process data
Cycles – macros – feedrates – offsets,
4 Output result
Actual machining – this is the main program objective
5 Stop program
Clear conditions,
This method will work well on a sin gle data in put (sin gle process), ev ery time For ex am ple,
the preceding five ge neric steps can rep angle machine re sent drill ing of a sin gle hole, at any desired lo ca tion
Now re place the ge neric terms with spe cific drill ing op er a tions (all five step num bers match):
1 Start program
same as
1 Start program
2 Input XYZ hole location
same as
2 Input data
3 Move to the new location
same as
3 Process data
4 Drill the hole
same as
4 cnc equipment Output results
5 Stop program
same as
5 Stop program
Al though only the ba sic drill ing pro cess notching machine illustrated, the or derly flow shows a clear con cept of
what is hap pen ing What is the ac tual re sult of this pro cess? Us ing the hole drill ing as an ex am ple,
one hole – and only one hole – has been drilled The sin gle pro cess does not need the IF func tion,
most stan dard pro grams use it daily, how ever in mac ros, the IF func tion rep re sents the sin gle
pro cess, such as a sin gle hole If more than one hole is needed, the sin gle pro cess is not sufficient
Mul ti ple Process
In the next stage, the same example will be explored, this time to drill more than a sin gle hole
The above top-down pro cess is not quite suf fi cient and a dif fer ent tech nique has to be used Be fore
think ing of a tech nique, think of a pro cess What has to change? We do not want to al ways start
and stop af ter drill ing the first hole, do we? We want to in put the next hole lo ca tion (item 2), move
to that lo ca tion (item 3), drill the hole at that lo ca tion (item 4), and – we want to re peat these three
steps un til all holes are done