Subroutines; Application; Subroutine Structure - Siemens SINUMERIK 880 Programming Manual

05.91
6

Subroutines

6.1

Application

If the same machining operation must be performed repeatedly when a workpiece is machined,
it can be entered as a subroutine and called as often as desired in the part program or by
means of manual data input.
The number of main programs and subroutines that can be stored at any one time depends on
the size of the part program memory. Subroutine numbers L1 to L799 are available for
programming. It is not possible to call subroutine L0 in a program as it is assigned to a special
system function.
Subroutine numbers L800 to L999 are reserved for SIEMENS purposes as far as they are not
required by the machine manufacturers.
Subroutines should preferably be programmed using incremental position data. The tool is set
to the start position in the part program before the subroutine call. The machining sequence at
the workpiece can then be repeated at various points on the workpiece without modifying the
dimensions in the subroutine.
6.2

Subroutine structure

A subroutine comprises:
• the beginning of the subroutine,
• the subroutine blocks,
• the end of the subroutine.
L230
Subroutine structure
The beginning of the subroutine comprises identifier SPF and the three-digit subroutine
number (see program key).
The end of the subroutine is used to return to the part program and is defined by the end
character M17.
M17 is written in the last block of the subroutine. It is permissible to write other functions
(except address L) in this block, i.e. a subroutine consists of at least two blocks.
© Siemens AG 1991 All Rights Reserved
SINUMERIK 880, (PG)
Beginning
Block Statements
M17 End of subroutine
6ZB5 410-0HD02
6 Subroutines
6.1 Application
6–1