L9_LAB: Label for a Subroutine (1 Node)
(Original Document)
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Function Description
The L9_LAB function block is used to label the starting point of a subroutine in the subroutine segment of user logic. This function block must be programmed in row1, column 1 of a network in the subroutine segment of user logic. L9_LAB is a one-node function block.
L9_LAB also serves as a default return from the subroutine in the preceding networks.
If you are executing a series of subroutine networks and you find a network that begins with L9_LAB, the system knows that the previous subroutine is finished, and it returns the logic scan to the node immediately following the most recently executed L9_JSR block.
NOTE: If you need I/O serviced while you are in the interrupt subroutine, you must use the L9_IMIO (read/write) function block in the same subroutine. If you do not, the I/O referenced in that subroutine will not get serviced until the appropriate segment is solved.
Representation
Parameters
Input Pin
Name
Data Type
Address Range
Meaning
Top
ENABLE
BOOL
–
ON = enables the subroutine specified by the number in SRNUM
Node
Node Type
Name
Data Type
Address Range
Meaning
Top
IN
SRNUM
UINT
1..1023
Integer value, identifies the subroutine you are about to execute
Range: 1 ... 1023
If more than 1 network begins with a L9_LAB function block with the same subroutine value, this will lead to an analyze event.
Output Pin
Name
Data Type
Address Range
Meaning
Top
ERR
BOOL
–
ON = event in the specified subroutine’s initiation