Programming of CNC Machines. Ken Evans

Figure 2-6 Operator Panel Courtesy FANUC FA America

      MDI mode can also be used during the execution of the program. Suppose the program is missing the command M03 S350 needed to turn on the spindle clockwise at 350 r/min, and the End-Of-Block character (;).To correct this omission, press the SINGLE BLOCK button and then the MDI button. Using MDI, you can enter functions M03 and S350 from the control panel keypad followed by the EOB character. Then, enter this command by pressing INPUT on the control panel. Press AUTO to reenter the program auto-cycle mode and then press CYCLE START to continue executing the program from memory. Changes of this sort (program edits) should be saved to overwrite the original program.

       Remote

      The Remote button is used for DNC (Direct Numerical Control) program operations when the program is too large for the controller memory and is executed (drip-fed) directly from a remote personal computer (PC) via Ethernet or memory card. USB cannot be used for DNC operations.

       OPERATION SELECT

      The following buttons are related to the automatic operation of the machine. Activating one of these buttons has an effect on the operation.

       Single Block

      The execution of a SINGLE BLOCK (SINGL BLOCK) of information is initiated by pressing this button to turn it ON. Each time the CYCLE START button is pressed, only one block of information will be executed. This switch can also be used if you intend to check the initial performance of a new program on the machine or when the momentary interruption of a machine’s work is necessary.

       Block Skip

      When this button is pressed and is active simultaneously with the auto-cycle mode, the controller skips execution of the program blocks that are preceded by the slash (/) symbol and that end with the end of block (;) character. For instance, if a section of the part program or a particular block of the program is not presently needed—but you would like to keep this information for future use—then place the block skip symbol (/) at the beginning of each such block. The BLOCK SKIP button is located on the control panel. If it is activated, then information contained in the blocks that are preceded by the symbol (/) will not be executed.

      Example:

      N100 G01 X2.810 Y3.256

      /N105 X3.253 Y2.864

      /N110 X3.800

      (Blocks N105 and N110 will be skipped.)

       Notes: The symbol (/) should be placed at the beginning of the block. If it is not, then all the information contained in the block preceding the symbol (/) will be executed, while the information following this symbol will be omitted.

       If the BLOCK SKIP is in the OFF condition, all blocks [regardless of the symbol (/)] will be executed.

       When transferring the program to punched tape or external computer, all program information [regardless of symbol (/)] is transferred.

       Opt Stop

      When this button is pressed, the OPTIONAL STOP mode is active. The OPTIONAL STOP function interrupts the automatic cycle of the machine if the program word M01 appears in the program. Quite often, function M01 is placed in the program after the work of a particular tool is completed or before a tool change. This enables you to perform chip removal or a routine measurement directly on the machine and, if necessary, make adjustments, and then rerun the same tool to correct inaccuracies.

       Teach

      If the TEACH button is available, you can use it to create/edit a program, positioning the axes manually by jogging (Teach-in Jog) or handle (Teach-in Handle) mode, and inputting the other required codes while in the MDI or Edit mode. When the Teach mode is used, the movements of the axes are recorded while in either Jog or Handle mode. Machine positions along the X-, Y-, and Z-axes obtained by this manual operation are stored in memory as a program position; they are used to create a program. These movements can then be executed just as with any program. Consult the manufacturer’s operator manual for detailed descriptions on the TEACH button’s proper use. Not all controls have this feature.

       Restart

      The RESTART button allows you to restart automatic operation at a specific place in the program by entering a desired line sequence number. This sometimes becomes necessary after tool breakage or some type of collision. When the proper data are entered, the control processes through the program until the block entered is reached; it then activates any required modal G, F, D, and H commands. Any needed auxiliary codes (M, S, T, and B) must be entered during the Restart process.

       MC Lock

      This function is known as MACHINE LOCK. Activating this mode inhibits axis movement on all of the axes. This button is used to check a new program on the machine through the controller. All movements of the tool are locked, while a program check is run on the computer and displayed on the screen. You can observe the position display on the screen; if any program errors are encountered, an alarm will be displayed. This function is especially useful for checking very large programs requiring a long cycle time to complete. This test is normally the first in a series (Program Test, Dry Run, and Single Block) of preliminary actions to be executed before full auto cycle mode is attempted. For any program test, all offsets should be set first. During MACHINE LOCK, all axes are locked. It is possible to unlock selected axes during this mode in order to inhibit axis movement in only one axis. This function is especially useful when inhibiting the Z-axis so that all X, Y movements can still be observed.

       Dry Run

      When you press the DRY RUN button during automatic cycle, all of the rapid and work feeds are changed to a feed set in the parameters instead of the programmed feed (usually rapid traverse feed rate). In this mode, you can control the feed rate by using the Feed Override switch. Consult the manufacturer manual for specific directions on the use of this function.

      DRY RUN is also used to check a new program on the machine without any work actually being performed by the tool. This is particularly useful on programs with long cycle times so you can progress through the program more quickly.

       Use caution when using this function. It is NOT intended for metal cutting.

       EXECUTION

      These three buttons are related to automatic operation of the machine. The first button temporarily stops the operation, the second starts automatic operation, and the last key merely indicates when a program stop is encountered. Their specific functions are described below:

       Cycle Stop (Feed Hold)

      Pressing the CYCLE STOP button during automatic operation will halt all feed movements of the machine. It will not stop the spindle r/min or affect the execution of tool changes on some machines. When the CYCLE STOP button is pressed, the LED located on the button goes on, and the LED located on the CYCLE START button goes off. This button is used when minor problems are encountered, such as coolant flow direction or when checking DISTANCE-TO-GO during setup. When the problem is remedied, press CYCLE START again to resume automatic cycle operation. It is not recommended using this button to interrupt a cut because the spindle does not stop; therefore, damage to the tool or part may occur. When pressed during the execution of the tapping or threading cycle, CYCLE STOP will take effect after the thread pass or the tap is withdrawn. If the tap breaks during the tapping cycle, the only way to stop the machine is by pressing the RESET button on the controller or the EMERGENCY STOP button.

       Cycle Start

      The CYCLE START button is used to start automatic operation. Use this button in order to begin the execution of a program from memory. When the CYCLE START button is pressed, the LED located above this button goes on and the active program will be executed to the end.