Standard
Rll Instructions
5–98
Standard RLL Instructions
Program Control Instructions
K aaa
The Goto Subroutine instruction allows a
section of ladder logic to be placed outside
the main body of the program execute only
when needed. There can be a maximum
of 64 GTS instructions and 64 SBR
instructions used in a program. The GTS
instructions can be nested up to 8 levels.
An error E412 will occur if the maximum
limits are exceeded. Typically this will be
used in an application where a block of
program logic may be slow to execute and
is not required to execute every scan. The
subroutine label and all associated logic is
placed after the End statement in the
program. When the subroutine is called
from the main program, the CPU will
execute the subroutine (SBR) with the
same constant number (K) as the GTS
instruction which called the subroutine.
By placing code in a subroutine it is only
scanned and executed when needed
since it resides after the End instruction.
Code which is not scanned does not
impact the overall scan time of the
program.
GTS
K aaa
SBR
Operand Data Type DL05 Range
aaa
Constant K 1–FFFF
When a Subroutine Return is executed in
the subroutine the CPU will return to the
point in the main body of the program from
which it was called. The Subroutine Return
is used as termination of the subroutine
which must be the last instruction in the
subroutine and is a stand alone instruction
(no input contact on the rung).
RT
The Subroutine Return Conditional
instruction is a optional instruction used
with a input contact to implement a
conditional return from the subroutine. The
Subroutine Return (RT) is still required for
termination of the Subroutine.
RTC
Goto Subroutine
(GTS)
(SBR)
Subroutine Return
(RT)
Subroutine Return
Conditional
(RTC)
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