Siemens SINUMERIK 828D Function Manual page 543

Nesting rules
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 subprogram1 calls subprogram2 in a search-suppressed area, subprogram2 remains search-suppressed.
IPTRUNLOCK in particular has no effect in subroutine 2.
Examples of nesting with two program levels
Nesting of search-suppressed program sections in 2 program levels.
Table 9-1
N10010 IPTRLOCK()
N10020 R1 = R1 + 1
N10030 G4 F1
...
N10040 Subprogram2
...
N20010 IPTRLOCK ()
...
N20020 IPTRUNLOCK ()
...
N20030 RET
...
N10050 IPTRLOCK()
N10060 R2 = R2 + 2
N10070 G4 F1
An interruption in a search-suppressed program section of the above program always returns N10030 G4 F1
block.
With implicit IPTRUNLOCK
Nesting of search-suppressed program sections in two program levels with implicit IPTRUNLOCK. The implicit
IPTRUNLOCK in subprogram 1 ends the search-suppressed area.
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
K1: Mode group, channel, program operation, reset response
; Interpretation of the blocks in an illustrative
sequence.
; Subprogram1 is prepared for the block search:
; Program level 1
;
; hold block
of the search-suppressed program section starts
;
; Interpretation of subprogram2
; Program level 2
; is ineffective
;
; is ineffective
;
;
;
;
;
; End of search-suppressed program section
9.8 Block search Type 5 SERUPRO
543