Programming of CNC Machines. Ken Evans
pressing this button while in one of the Operation modes HOME, JOG, INC JOG or MPG the spindle will start rotation in the counterclockwise (CCW) direction. The spindle r/min is set by using the SPDL DEC, SPDL 100%, or SPDL INC buttons. The last r/min commanded in the program or used while in this mode is retained and will restart upon pressing the SPDL 100% button.
AXIS/DIRECTION
These buttons are used to select the Manual feed axis direction. Pressing these buttons executes movement along the selected axis in the selected direction by jog feed (or step feed) when the corresponding button is set to on in the jog feed mode (or step feed mode). The same is true for each of the axes where buttons are present.
Figure 14 Axis Direction Buttons
−X
When pressed, this button executes movement along the X axis in the negative direction with respect to the coordinate system.
+Z
When pressed, this button executes movement along the Z axis in the positive direction with respect to the coordinate system.
−Z
When pressed, this button executes movement along the Z axis in the minus direction with respect to the coordinate system.
+X
When pressed, this button executes movement along the X axis in the positive direction with respect to the coordinate system.
Note: The Y axis buttons for milling machines are not depicted in the operator panel in Figure 1. The following are their descriptions.
−Y
When pressed, this button executes movement along the Y axis in the negative direction with respect to the coordinate system.
+Y
When pressed, this button executes movement along the Y axis in the positive direction with respect to the coordinate system.
TRVRS-Rapid Traverse
Caution: When using this rapid traverse function be sure that all machine movements will not cause interference during motion!
Press this button to activate jog feed at a rapid traverse rate. Use this button to perform rapid movements along a previously chosen axis. For example, press the button TRVRS then the X positive button, the X axis will move at rapid traverse until the button is released.
Rapid Traverse Override (%)
(Not shown on this operator panel model)
Some operator panels include a % override dial or buttons that can be used to control the rapid feed rate. This switch or these buttons are used to reduce the rapid feed rate (G00). If it is positioned at 100, this corresponds to 100% of the rapid feed rate that the machine can generate. Buttons are commonly incremented in steps of 10, 25, 50 and 100%.
Figure 14b Rapid Traverse Override Buttons
In the above illustration, F0 corresponds with 10% (as determined by parameter).
COOLANT
During manual or automatic operation, these buttons may be used to activate or stop the flow of coolant.
CLNT ON-Coolant ON
When this button is pressed the supply of coolant is started.
CLNT OFF-Coolant OFF
When this button is pressed the supply of coolant is stopped.
CLNT AUTO-Coolant Auto Mode
This button is pressed to activate the automatic start and stoppage of coolant flow during program execution when called by program words M08 and M09 respectively.
Figure 16 Common Control Panel
CONTROL PANEL
The control panel described here is quite typical of the control panels used on CNC machines. The control panel switches and buttons may be distributed differently on the panel for each individual machine; however, the purpose and function of each switch and button remains the same. Some control panels are equipped with additional buttons or switches not shown here. Definitions and applications of these buttons or switches can be found in the manufacturer instruction manuals for the machines.
The control panel is located at the front of the machine and is equipped with a CRT and with various buttons and switches, as illustrated in Figure 16.
Two items not shown on this controller that are common on many modern controls are a 3.5 floppy disk and PCMCI (Portable Computer Memory Card Interface) slot. These are both used as a file storage medium and a method for file transfer. The floppies typically hold a maximum of 1.44 mega bytes (MB) of data while PCMCI cards range from 40MB to 200MB. The 1.44 MB floppy can store the equivalent of 3600 meters of paper tape. Both are widely used to store part programs offset data and NC parameter information. Because of emerging technologies in computer industry, the storage and data transfer medium described here are changing and improving rapidly and some controllers are now being equipped with a Universal Serial Bus (USB) drive interface.
A detailed description for the use of each button and the purpose of the particular sections of the control panel are presented in the following sections:
POWER-ON & POWER-OFF
These buttons are used to activate/deactivate the power to the control. The ON button is typically green in color and when it is ON, the key is lit. The OFF button is typically red in color and when the power is turned OFF to the control, the key is lit. At startup of the main power to the machine, the OFF button is lit.
Press theses buttons to turn CNC power ON and OFF.
Figure 17 On Button
Figure 18 Off Button
Notes: The control is always turned ON after the MAIN POWER switch is ON. The switch is located on the door of the control system and is typically at the back or side of the machine. The control is always turned OFF before the MAIN POWER switch is turned OFF.
CRT DISPLAY
This is the television-like screen on which all the program characters and data are shown. Sizes vary from around 9 inches to approximately 15 inches. Displays are color, monochrome or Liquid Crystal Displays (LCD).
Reset Key
Pressing this button resets or cancels an alarm and can be used for cancellation of an automatic operation. An alarm can only be cancelled if its cause has been eliminated.
Figure 19 Reset Button
When the reset button is pressed during automatic operation, all program commanded axis feeds and spindle revolutions are cancelled. The program will return to its starting block when this button is pressed.
Help Key
Pressing this key gives the operator help screens on