Calling block sequences (L SEQUENCE)

Block sequences are contiguous program parts or single NC blocks in the current NC program or a global subroutine which can be executed once or several times with L SEQUENCE.

A block sequence is defined by specifying the start and end identifications by:

Notice

notice

Every call of a block sequence is identical to a subroutine call. The same rules on nesting depth apply as for global subroutines.

Attention

attention

Context evaluation:

The program context in the subroutine is not set up until the first NC line of the block sequence is executed. All previous NC lines passed through are not evaluated. Previously defined variables/coordinate systems, parameters, modal statements, etc. are neither created nor initialised. Therefore, they are unknown or not available in the block sequence.

In particular when executing block sequences with control block statements ($IF-$ELSE-$ENDIF, $SWITCH,..), users must ensure themselves that they pass through the entry and return points without conflict.

Syntax of L SEQUENCE when using block numbers:

L SEQUENCE [ [ NAME=<string> ] N<expr> [ N<expr> ] [ REPEAT<expr> ] [ ENDTAG ] ]

NAME=<string>

Name of the current subroutine or a global subroutine in which the block sequence makes a pass. Optional: If no name is programmed, the block sequence passes through the current NC program.

N<expr>

Number of the first block to be executed (start number, start of block sequence)

N<expr>

Number of the last block to be executed (return number, end of block sequence) Optionally, if both block numbers are identical, only this block is executed.

REPEAT<expr>

Number of repetitions of a block sequence, positive integer > 1. Optionally, if REPEAT is not specified, the block sequence makes a single pass.

ENDTAG

Marks the call L SEQUENCE itself as an additional valid end of the block sequence. Optionally, if both ENDTAG and a return number N.. are programmed at the same time, the sequence end found first is the valid one.

The controller searches for the programmed N (block) numbers in the specified NC program (which can also be the same program that calls up the command). The two N numbers mark the first and last NC blocks to be executed in the block sequence; NC blocks outside this block sequence are not executed.

It is recommended to use a unique ascending numbering format for the NC blocks.

The start and return numbers can also be swapped in the command when programmed. In the NC program, however, the block sequence always passes through from the lower N number to the higher N number.

An error message is issued if the start or return number is not found.

If the block sequence is to be executed multiple times (REPEAT > 1), the program starts at the start number again at the end of the block sequence. Once all passes have been executed, the program returns from the block sequence and the rest of the program sequence is continued.

If only an N number was specified in the command, only this line is passed. This corresponds to a call with two identical N numbers.

The L SEQUENCE call itself may be located in the block sequence defined by the N numbers. When the same call is read again, the following two reactions are possible:

Without ENDTAG the recall is ignored and the block sequence is executed until the return number.

With ENDTAG the L SEQUENCE call is marked as the valid sequence end and the block sequence is terminated.

Programing Example

prg_example

Calling block sequences (L SEQUENCE)

Repeat block sequence between 2 block numbers once:

...

N20 ...                           ;Start number

...

N50 ...                           ;Return number

...

N80 L SEQUENCE [N20 N50]          ; or..

N80 L SEQUENCE [N20 N50 REPEAT=1]

...

Repeat block sequence between 2 block numbers several times:

...

N20 ...                           ;Start number

...

N50 ...                           ;Return number

...

N80 L SEQUENCE [N20 N50 REPEAT=4]

...

Block sequence between 2 block numbers. Bracketed sequence call is ignored when the block sequence is executed since ENDTAG is not set:

...

N20 ...                           ;Start number

...

N40 L SEQUENCE [N20 N80]

...

N80 ...                           ;Return number

...

Block sequence between 2 block numbers. Bracketed sequence call is the first block sequence end found since ENDTAG is set:

...

N20 ...                           ;Start number

...

N40 L SEQUENCE [N20 N80 ENDTAG]

...

N80 ...                           ;Return number

...

Block sequence between 2 block numbers with ENDTAG. ENDTAG is not relevant since the return number is before the sequence call:

...

N20 ...                           ;Start number

...

N50 ...                           ;Return number

...

N80 L SEQUENCE [N20 N50 REPEAT=4 ENDTAG]

...

Repeat a single NC block several times:

...

N20 ...                           ;Start number

...

N80 L SEQUENCE [N20 REPEAT=4]     ; or..

N80 L SEQUENCE [N20 N20 REPEAT=4]

...

Block sequence between 1 block number and ENDTAG:

...

N20 ...                           ;Start number

...

N80 L SEQUENCE [N20 ENDTAG]

...

Repeat block sequence between 2 block numbers several times. Sequence call is before the block sequence:

...

N80 L SEQUENCE [N100 N150 REPEAT=4]

...

N100 ...                           ;Start number

...

N150 ...                           ;Return number

Nested multiple call of block sequences between block numbers:

...

N40 L SEQUENCE [N60 N150 REPEAT=2] ;Sequence call 1

...

N60 ...                            ;Start number 1

...

N90 ...                            ;Start number 2

...

N120 ...                            ;Return number 2

...

N130 L SEQUENCE [N90 N120 REPEAT=4] ;Sequence call 2

...

N150 ...                            ;Return number 1

...

Repeat block sequence between 2 block numbers in a global subroutine several times:

...

N20 ...

...

N80 L SEQUENCE [NAME="glob_1.nc" N50 N150 REPEAT=4]

...

Nested multiple calls of block sequences in the current program and a global subroutine between block numbers:

...

N20 L SEQUENCE [N60 N150 REPEAT=2] ;Sequence call 1

...

N60 ...                            ;Start number 1

...

N80 L SEQUENCE [NAME="glob_1.nc" N50 N150 REPEAT=3]   ;Sequence call 2

...

N150 ...                           ;Return number 1

...

Syntax of L SEQUENCE when using jump labels (string labels):

L SEQUENCE [ [ NAME=<string> ] [<START>] [ [<END>] ] [ REPEAT<expr> ] [ ENDTAG ] ]

NAME=<string>

Name of the current subroutine or a global subroutine in which the block sequence makes a pass. Optional: If no name is programmed, the block sequence passes through the current NC program.

[<START>]

Start label of first block to be executed (start of block sequence)

[<END>]

End label of last block to be executed (return, end of block sequence) Optionally, if both labels are identical, only this block is executed.

REPEAT<expr>

Number of repetitions of a block sequence, positive integer > 1. Optionally, if REPEAT is not specified, the block sequence makes a single pass.

ENDTAG

Marks the call L SEQUENCE itself as an additional valid end of the block sequence. Optionally, if both ENDTAG and an end label are programmed at the same time, the sequence end found first is the valid one.

The controller searches for the programmed jump labels in the specified NC program (which can also be the same program that calls the command). The two jump labels mark the first and last NC blocks to be executed in the block sequence; - NC blocks outside this block sequence are not executed.

Jump labels are set at block start or directly after the block number. An error message is issued if the start or return label is not found.

If the block sequence is to be executed multiple times (REPEAT > 1), the program starts at the start label again when it reaches the end of the block sequence. Once all passes have been executed, the program returns from the block sequence and the rest of the program sequence is continued.

If only a single start label was specified in the command, only this line is passed. This corresponds to a call with two identical N numbers.

The L SEQUENCE call itself may be located in the block sequence defined by the jump labels. When the same call is read again, the following two reactions are possible:

Without ENDTAG the recall is ignored and the block sequence is executed up to the return label.

With ENDTAG the L SEQUENCE call is marked as the valid sequence end and the block sequence is terminated.

Programing Example

prg_example

Calling block sequences (L SEQUENCE)

Repeat block sequence between 2 jump labels once:

...

N20 [STARTLBL] ...                           ;Start label

...

N50 [ENDLBL] ...                             ;Return label

...

N80 L SEQUENCE [[STARTLBL] [ENDLBL]] ;oder..

N80 L SEQUENCE [[STARTLBL] [ENDLBL] REPEAT=1]

...

Repeat block sequence between 2 jump labels several times:

...

N20 [STARTLBL] ...                            ;Start label

...

N50 [ENDLBL] ...                              ;Return label

...

N80 L SEQUENCE [[STARTLBL] [ENDLBL] REPEAT=4]

...

Block sequence between 2 jump labels. Bracketed sequence call is ignored when the block sequence is executed since ENDTAG is not set:

...

N20 [STARTLBL] ...                            ;Start label

...

N40 L SEQUENCE [[STARTLBL] [ENDLBL]]

...

N80 [ENDLBL]...                               ;Return label

...

Block sequence between 2 jump labels. Bracketed sequence call is the first block sequence end found since ENDTAG is set:

...

N20 [STARTLBL]...                             ;Start label

...

N40 L SEQUENCE [[STARTLBL] [ENDLBL] ENDTAG]

...

N80 [ENDLBL] ...                              ;Return label

...

Block sequence between 2 jump labels with ENDTAG. ENDTAG is not relevant since the return label is before the sequence call:

...

N20 [STARTLBL]...                              ;Start label

...

N50 [ENDLBL] ...                            ;Return label

...

N80 L SEQUENCE [[STARTLBL] [ENDLBL] REPEAT=4 ENDTAG]

...

Repeat a single NC block several times:

...

N20 [STARTLBL] ...                            ;Start label

...

N80 L SEQUENCE [[STARTLBL] REPEAT=4]          ;or..

N80 L SEQUENCE [[STARTLBL] [STARTLBL] REPEAT=4]

...

Block sequence between 1 jump label and ENDTAG:

...

N20 [STARTLBL] ...                            ;Start label

...

N80 L SEQUENCE [[STARTLBL] ENDTAG]

...

Repeat block sequence between 2 jump labels several times. Sequence call is before the block sequence:

...

N80 L SEQUENCE [[STARTLBL] [ENDLBL] REPEAT=4]

...

N100 [STARTLBL] ...                            ;Start label

...

N150 [ENDLBL] ...                             ;Return label

Nested multiple call of block sequences between jump labels:

...

N40 L SEQUENCE [[STARTLBL1] [ENDLBL1] REPEAT=2] ;Sequence call 1

...

N60 [STARTLBL1] ...                               ;Start label 1

...

N90 [STARTLBL2] ...                               ;Start label 2

...

N120 [ENDLBL2] ...                                ;Return label 2

...

N130 L SEQUENCE [[STARTLBL2] [ENDLBL2] REPEAT=4]  ;Sequence call 2

...

N150 [ENDLBL1]...                                 ;Return label 1

...

Repeat block sequence between 2 jump labels in a global subroutine several times:

...

N20 ...

...

N80 L SEQUENCE [NAME="glob_1.nc" [SUP1] [EUP1] REPEAT=4]

...

Nested multiple calls of block sequences in the current program and a global subroutine between jump labels:

...

N20 L SEQUENCE [[STARTLBL] [ENDLBL] REPEAT=2]      ;Sequence call 1

...

N60 [STARTLBL] ...                                 ;Start label 1

...

N80 L SEQUENCE [NAME="glob_1.nc" [SUP1] [EUP1] REPEAT=3] ;Sequence call 2

...

N150 [ENDLBL]...                                   ;Return label 1

...