Siemens SINUMERIK 840D sl Programming Manual page 503

Special aspects
● Block display with suppressed single block machining
The current block display can be suppressed in subprograms using DISPLOF. If DISPLOF
is programmed together with SBLOF, for single block stops within the subprogram, the
subprogram call is displayed.
● Suppression of single block machining with asynchronous subprograms (ASUB)
In order to execute an ASUB with active single block machining in one step, a PROC
statement must be programmed in the ASUB with SBLOF. This also applies to the function
"Editable system ASUB" (MD11610 $MN_ASUP_EDITABLE).
If the single block stop in the system or user ASUB is suppressed by programming SBLOF
in the PROC line or using the settings in machine data
MD10702 $MN_IGNORE_SINGLEBLOCK_MASK (bit0 = 1 or bit1 = 1), then the single
block stop can be reactivated by programming SBLON in the ASUB.
If the single block stop in the user ASUB is suppressed using the setting in machine data
MD20117 $MC_IGNORE_SINGLEBLOCK_ASUP, the single block stop cannot be
reactivated by programming SBLON in the ASUB.
● Special features for various single block machining types
– "SB2: Arithmetic block" AND MD10702 $MN_IGNORE_SINGLEBLOCK_MASK,
– "SB3: single block fine":
● Suppression of single block machining in nested programs
If SBLOF was programmed in the PROC statement in a subprogram, then execution is
stopped at the subprogram return with M17. That prevents the next block in the calling
program from already running. If, in a subprogram with SBLOF, without SBLOF in the PROC
statement, a suppression of single block machining is activated, execution is only stopped
after the next machine function block of the calling program. If that is not wanted, SBLON
must be programmed in the subprogram before the return (M17). Execution does not stop
for a return to a higher-level program with RET.
Examples
Example 1: Suppressing single block machining within the NC program
Initial situation: Single block machining is active.
Program code
N10 G1 X100 F1000
N20 SBLOF
N30 Y20
N40 M100
N50 R10=90
N60 SBLON
N70 M110
N80 ...
The area between N20 and N60 is executed as one step in single block mode.
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
Bit 12 = 1:
→ The program is not stopped in the SBLON block.
→ The SBLOF command is suppressed.
Comment
; Switch off single block machining
; Reactivate single block machining
Work preparation
3.2 Subprogram technique
503