5. Special M codes
In principle, a block which includes any of the following M codes, which specify the execution
of special functions, must not contain any other codes. When it is impossible to avoid specifying
an M code together with another code in the same block, refer to the relevant description in the
manual supplied by the machine–tool builder. Failure to follow the specified procedure may
result in damage to the machine or injury to the user.
S Forming mode/forming mode cancel
S Workpiece clamp/unclamp
S Nibbling mode/nibbling mode cancel
S Switching between punch mode and laser mode
6. Function involving a rotation axis
When programming polar coordinate interpolation or normal–direction (perpendicular) control,
pay careful attention to the speed of the rotation axis. Incorrect programming may result in the
rotation axis speed becoming excessively high, such that centrifugal force causes the chuck to
lose its grip on the workpiece if the latter is not mounted securely.
Such mishap is likely to damage the tool, the machine itself, the workpiece, or cause injury to
7. Absolute/incremental mode
If a program created with absolute values is run in incremental mode, or vice versa, the machine
may behave unexpectedly.
8. Plane selection
If an incorrect plane is specified for circular interpolation, helical interpolation, or a canned cycle,
the machine may behave unexpectedly. Refer to the descriptions of the respective functions for
9. Torque limit skip
Before attempting a torque limit skip, apply the torque limit. If a torque limit skip is specified
without the torque limit actually being applied, a move command will be executed without
performing a skip.
10. Programmable mirror image
Note that programmed operations vary considerably when a programmable mirror image is
11. Compensation function
If a command based on the machine coordinate system or a reference position return command
is issued in compensation function mode, compensation is temporarily canceled, resulting in the
unexpected behavior of the machine.
Before issuing any of the above commands, therefore, always cancel compensation function