DVP-ES2/EX2/EC5/SS2/SA2/SX2/SE&TP Operation Manual - Programming
5.1 Step Ladder Instruction [STL], [RET]
Mnemonic
Operands Function Program steps
Controllers
STL S0~S1023 Starts STL program 1
Explanation:
STL Sn constructs a step point. When STL instruction appears in the program, the main program will
enter a step ladder status controlled by steps. The initial STL program has to start from S0 ~ S9 as
initial step points. The No. of Step points cannot be repeated.
Mnemonic
Operands Function Program steps
RET None Ends STL program 1
Explanation:
RET instruction indicates the end of a step ladder program starting from S0 ~ S9, i.e. the execution
returns to main program after RET is executed. Maximum 10 initial steps (S0 ~ S9) can be applied
and every initial step requires a RET instruction as an end of STL program. With the step ladder
program composed of STL/RET instructions, SFC can perform a step by step control process.
Program Example:
M1002
ZRST S0 S127
SET S0
SET S20
Y0
SET S30
Y1
SET S40
Y2
S0
RET
END
X0S0
S
S20
S
X1
S30
S
X2
S40
S
X3
S0
S20
S30
S40
S0
M1002
X0
X1
X2
X3
Y0
Y1
Y2