Delta Electronics Programmable Logic Controller DVP-PLC - Manual (Page 175)

4 Step Ladder Instructions
DVP-PLC Application Manual
4-5
4. Repeated Use of Timer:
The timers in EH/EH2/SV series MPU are the same as general
output points and can be repeatedly used in different steps.
This is one of the features of the step ladder diagram.
However, in a general ladder diagram, it is better not be
repeatedly use the output coil. Also avoid using the No. of the
output coil used by a step after the step ladder diagram returns
to a general ladder diagram.
Note: See the figure in the right. The timers in ES/EX/SS/SA/
SX/SC series MPU can be used repeatedly in non-adjacent
steps.
S20
S30
S40
X1
X2
TMR T1 K10
TMR T2 K20
TMR T1 K30
5. Transfer of Step:
SET Sn and OUT Sn instructions are used to enable (or transfer to) another step. When the control power is
shifted to another step, the status of the previous step S and the action of the output point will be cleared. Due to
that there can be many step control sequences (i.e. the step ladder diagram starting with S0 ~ S9) co-existing in
the program. The transfer of a step can take place in the same step sequence, or be transferred to different step
sequence. Therefore, there are some slight differences regarding how to use SET Sn and OUT Sn. See the
explanations below.
SET Sn Used for driving the next
step in the same
sequence. After the
transition, all output from
the previous status will be
cleared.
Y10
SET S12
SET S14
S10
S
X0
S12
S
X1
Y11
When SET S12 instruction is executed,
S10 will transfer to S12, and S10 and all
its outputs (Y10) will be cleared.
OUT Sn Used for returning to the initial step in the same step sequence. Also for jumping up/down to
non-adjacent steps in the same sequence, or separating steps in different sequences. After the
transition, all output from the previous status will be cleared.
c Returning to the
initial step in the
same sequence.
d Jumping up/down
to non-adjacent
steps in the same
sequence.
SFC: Ladder diagram:
S0
S21
S24
S25
X7
X2
OUT
OUT
S24
S21
S
S0
S
S23
S
X2
S24
S
S25
S
S0
X7
RET
Using OUT S24
Using OUT S0
S25 returns to the initial
step S0 by using OUT.
Driving the jumping
of step
Return to initial step