Siemens Sinumerik 840D sl Programming Manual page 485

Rules for nesting:
The following features regulate the interaction between NC commands IPTRLOCK and
IPTRUNLOCK with nesting and end of subroutine:
1. IPTRLOCK is activated implicitly at the end of the subroutine in which IPTRUNLOCK is
called.
2. IPTRLOCK in an untraceable section has no effect.
3. If subroutine 1 calls subroutine 2 in an untraceable section, the whole of subroutine 2
remains untraceable. IPTRUNLOCK in particular has no effect in subroutine 2.
For more information, see
/FB1/ Function Manual, Basic Functions; Mode Group, Channel, Program Operation Mode
(K1).
System variables
An untraceable section can be detected in the parts program with $P_IPTRLOCK.
Automatic interrupt pointer
The automatic interrupt pointer automatically defines a previously defined coupling type as
untraceable. The machine data for
• electronic gearbox with EGON
• axial leading value coupling with LEADON
are used to activate the automatic interrupt pointer. If the programmed interrupt pointer and
interrupt pointer activated with automatic interrupt pointers overlap, the largest possible
untraceable section will be generated.
Job planning
Programming Manual, 02/2011, 6FC5398-2BP40-1BA0
8.5 Preventing program position for SERUPRO (IPTRLOCK,
Path traversing behavior
485