Siemens SINUMERIK 840D sl Programming Manual page 851

It is also possible to define untraceable sections in part program sections that the NC cannot yet
re-enter. When the program is interrupted, the NC notes the last block that was processed that
can then be searched for via the HMI user interface.
Syntax
IPTRLOCK
IPTRUNLOCK
The commands are located in a part program line and allow a programmable interruption
pointer
Meaning
IPTRLOCK:
IPTRUNLOCK:
Both commands are only permitted in part programs, but not in synchronous actions.
Example
Nesting of untraceable program sections in two program levels with implicit "IPTRUNLOCK".
Implicit "IPTRUNLOCK" in subprogram 1 ends the untraceable section.
Program code
N10010
N10020
N10030
...
N10040 subprogram2
...
N20010
...
N20020
N20030
...
N10060
N10070
N100 G4 F2
The interruption pointer then produces an interruption at 100 again.
Further information
Acquiring and finding untraceable sections
Untraceable program sections are identified with language commands "IPTRLOCK" and
"IPTRUNLOCK".
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
Start of untraceable program section
End of untraceable program section
IPTRLOCK()
R1 = R1 + 1
G4 F1
IPTRLOCK ()
IPTRUNLOCK ()
RET
R2 = R2 + 2
RET
Comment
; Hold block of the search-suppressed program sec-
tion starts.
; Interpretation of subprogram 2.
; Ineffective, repeated start.
; Ineffective, end at another level.
; End of search-suppressed program section.
; Main program is continued.
Work preparation
3.14 Path traversing behavior
851