HEIDENHAIN TNC 320 (340 55x-03) - Manual (Page 208)

208 8 Programming: Cycles
8.1 W
o
rk
ing with Cy
cles
8.1 Working with Cycles
Frequently recurring machining cycles that comprise several working
steps are stored in the TNC memory as standard cycles. Coordinate
transformations and other special cycles are also provided as standard
cycles (for an overview, See “Cycles Overview,” page 210).
Fixed cycles with numbers 200 and above use Q parameters as
transfer parameters. Parameters with specific functions that are
required in several cycles always have the same number: For
example, Q200 is always assigned the set-up clearance, Q202 the
plunging depth, etc.
Machine-specific cycles
In addition to the HEIDENHAIN cycles, many machine tool builders
offer their own cycles in the TNC. These cycles are available in a
separate cycle-number range:
„ Cycles 300 to 399
Machine-specific cycles that are to be defined through the CYCLE
DEF key
„ Cycles 500 to 599
Machine-specific cycles that are to be defined through the TOUCH
PROBE key
Sometimes, machine-specific cycles also use transfer parameters that
HEIDENHAIN already used in the standard cycles. The TNC executes
DEF-active cycles as soon as they are defined (See also “Calling
cycles” on page 211). It executes CALL-active cycles only after they
have been called (See also “Calling cycles” on page 211). When DEF-
active cycles and CALL-active cycles are used simultaneously, it is
important to prevent overwriting of transfer parameters already in use.
Use the following procedure:
 As a rule, always program DEF-active cycles before CALL-active
cycles.
 If you do want to program a DEF-active cycle between the definition
and call of a CALL-active cycle, do it only if there is no common use
of specific transfer parameters.
Fixed cycles sometimes execute extensive operations.
For safety reasons, you should run a graphical program
test before machining (See “Test run” on page 453).
Refer to your machine manual for a description of the
specific function.