CNC Control Setup for Milling and Turning:. Peter Smid
Key
In the majority of CNC applications, the Custom selection key is used by the machine tool manufacturers for some unique activities of their CNC machine. For example, by pressing the Custom key, you may find procedures related to automatic tool and pallet changers,
In CNC programming, the word address refers to any letter used in the part program. For example, rapid motion G00 uses the G-address, tool change command M06 uses the M-address, and spindle speed S1200 (r/min) uses the S-address. These are just some of many addresses that are used in a typical part program.
The control panel keyboard is not just an exclusive address oriented keyboard, as it also includes digits and special symbols. In reality, the control system keyboard is a multifunctional alpha-numerical keyboard, which is actually a description used by some control systems.
Note that the keys containing letters also contain secondary characters. Grouping of the letters is designed to be convenient for CNC program data entry, and does not follow the common QWERTY keyboard layout.
Secondary characters are accessible via the Shift key. Not all secondary characters may be available, even if they appear on the keyboard. A pair of parentheses ( ) is used for inclusion of comments into the program, while square brackets [ ] are used only in macros. Macros also use the # symbol, equal sign =, asterisk * for multiplication, plus sign + for addition. From the numeric pad, macros also use subtraction sign - and forward slash / for divisions. Question mark ?, comma ‘,’, ampersand @, and the ‘at’ symbol ‘&’ are not normally used in part programs. SP is a symbol for ‘space’ to separate words.
As described already, the shift key is used the same way on the control panel as it is used on standard computer keyboard - it selects the secondary character, if available.
Numeric section of the keyboard contains only primary keys - no shift is required - it covers all digits from 0 to 9 as well as the negative sign and the decimal point. There is also a symbol for the forward slash, used as a block skip symbol in CNC programming.
There are three Edit keys on the control panel. They are used to edit programs stored in the CNC memory:
| ▪Alter | ... changes existing program entry |
| ▪Insert | ... adds a new entry into an existing program |
| ▪Delete | ... removes program entry |
Both Page and Cursor keys are navigational keys. They narrow down the available screen selections:
Page refers to a single display of the control screen. For example, a long program may not fit on a single screen and can be viewed only by scrolling from one page to the next, in ascending or descending order. Each time the Page key is pressed, another display screen will appear. Page-Up and Page-Down arrows select the direction of the page scrolling.
Cursor is normally used on the selected page. Its main purpose is to narrow down the selection within a page. Vertical cursor arrows are used to select a particular line displayed on the screen, while horizontal cursor arrows are use to select a particular item with the selected line.
EOB or E-O-B is just a short form for the End-Of-Block character. When entering a part program into the control system in Edit or MDI mode, each program block has to be separated from the next program block. End-Of-Block key is used for that purpose.
CAN is the Cancel key. As the name suggests, this key is used to cancel an erroneous data entry.
INPUT is a special key used for data settings. Unlike the INSERT key, it is not used for program data. Its main use is to set various offsets, settings, parameters, etc.
Do not confuse INPUT with INSERT
INPUT is used for data settings INSERT is used to add program data
Pressing the RESET key, many default conditions are restored. One of the most common use of this key is to cancel alarm or error condition.
Keep in mind that the actual cause of any alarm has to be addressed first, and the problem resolved before the Reset key can become functional.
The HELP key is quite self-explanatory - it provides details relating to various commands - commonly used in MDI mode. Various alarm details, as well as details relating to operation methods and parameter table can be found here.
The control system and its display/keyboard portion is closely connected to the operational features of the CNC machine, the Operation Panel. The next chapter will cover this subject in detail.
| 5 | OPERATION PANEL |
The part of the control system that is designed and manufactured by the machine tool builder (not the control system builder) is called the Operation Panel. This panel is much richer in visible features than the Control Panel and consists of the following major groups:
▪Main buttons and switches
▪Status indicator lights