Expression Of Step Ladder - Mitsubishi Electric FX3G SERIES Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
35.2.3

Expression of step ladder

Step ladder programs and SFC programs are substantially the same as described above, but actual programs are
expressed as shown below.
A step ladder program is expressed as a relay ladder, but it can be created according to the machine control flow
using state relays.
<Step ladder>
M8002
SET
STL
X000
SET
Start
STL
Y023
Y021
X001
SET
STL
Y021
Y023
X002
SET
STL
T0
T0
SET
STL
Y023
Y021
X003
SET
STL
Y021
Y023
X002
S0
It is necessary to input the RET
instruction in a program.
786
S0
S0
Process of S0
S20
S20
Moving
Process of S20
forward
S21
S21
Moving
Process of S21
backward
Can be converted
S22
each other
S22
Process of S22
K50
S23
S23
Moving
Process of S23
forward
S24
S24
Moving
Process of S24
backward
RET
END
<SFC program>
Ladder block
M8002
SET S0
SFC block
State number and transfer condition
number are indicated.
0
X000
0
Start
Y023
20
X001
1
Y021
21
X002
2
22
T0
3
Y023
23
X003
4
Y021
24
X002
5
S0
RET and END instructions are
RET END
automatically written when a program
is input in GX Developer.
35 SFC Program and Step Ladder
35.2 Step Ladder
Program for setting to
ON an initial state relay
TRAN
Moving
Y021
forward
TRAN
Moving
Y023
backward
TRAN
Internal
T0
K50
circuit
TRAN
Moving
Y021
forward
TRAN
Moving
Y023
backward
TRAN