Program Header - Siemens SIMATIC S5 Manual

Fig. 2/1 5 Structure of a machining program with program number 33
The machining program always has a program header and a final statement. The final statement
has the special identifier M02 at the end. The length of individual statements can vary.

2.6.2 Program Header

The program header is generated automatically by COM247 when the machining program is
created at the PG.
The header includes the following:
The program identifier:
L = subroutine,
The program number (maximum three characters) . DB number of the data block
A text with a maximum of 58 characters (selected as required)
Example:
this is a main program in DB5 <LF>
L12 this is a subroutine in DB12 <LF>
The difference between main programs and subroutines is simply of documentary interest, the
module does not distinguish between them, so that a program can be used both as a main
program and a subroutine.
Recursive or reciprocal program calls are, however, not permitted.
Program header
Statements of the
machining program
Final statement: program end
2-31