8 Basic CNC Programming
8.4 NC Codes
116
Info Table: Selecting a Plane for Circular Interpolation
Code
Selects
Plane
Arc Center Coordinates
Specification
G17
XY
I for the X axis, J for the Y axis
G18
XZ
I for the X axis, K for the Z axis
G19
YZ
J for the Y axis, K for the Z axis
8.4.7.
H Code: lnput Selection Number
The H code is used to specify inputs and outputs in robot integration (see
12 Automation lntegration, pg.
Use the H code in conjunction with:
The wait codes G25 and G26 to specify the input number.
The H code and input must be specified.
The transmit codes M25 and M26 for interfacing with robots or other external devices to specify
the output number.
The H code and input must be specified.
H codes specify inputs and outputs as defined in the table below.
Info Table: H Code
H Code
H11
H12
H13
H14
Input specified for Wait
Codes G25 and G26
1
2
3
4
Output specified for
Transmit codes M25 and
M26
1
2
3
4
8.4.8.
I Code: X Axis Coordinate of Center Point
The I code specifies the X coordinate of the center of an arc or circle. If no I code is specified when
specifying an arc or circle, the system uses the current X axis location as the X axis center of the arc.
The I code is used in both absolute and incremental programming modes. In Fanuc mode, all arc centers
are specified in incremental mode.
The value following the I code is interpreted differently in absolute and incremental programming
modes, as follows:
Info Table: I Code in Absolute and Incremental Modes
Mode
Activated by
I value specifies: