Delta Electronics Programmable Logic Controller DVP-PLC - Manual (Page 178)

4 Step Ladder Instructions
DVP-PLC Application Manual 4-8
Single sequence: There is only one sequence without alternative divergence, alternative convergence, simultaneous
divergence and simultaneous convergence in a program.
Complicated single sequence: There is only one sequence with alternative divergence, alternative convergence,
simultaneous divergence and simultaneous convergence in a program.
Multiple sequences: There are more than one sequence in a program, maximum 10 sequences, S0 ~ S9.
5. Separation of sequence: Multiple sequences are allowed to be written into the step ladder diagram.
a) See the diagram in the right hand side. There are two
sequences S0 and S1. The program writes in S0 ~ S30 first
and S1 ~ S43 next.
b) You can designate a step in the sequence to jump to any step
in another sequence.
c) When the condition below S21 is true, the sequence will jump
to step S42 in sequence S1, which is called “separating the
step”.
S0
S21
S30
OUT
OUT
S1
S41
S43
OUT
S42
6. Restrictions on diverging sequence: See 4.5 for example
a) You can use maximum 8 diverged steps in a divergence sequence.
b) You can use maximum 16 loops in multiple divergence sequences or in simultaneous sequences combined into
one sequence.
c) You can designate a step in the sequence to jump to any step in another sequence.
7. Reset of the step and the inhibiting output:
a) Use ZRST instruction to reset a step to be Off.
b) Make M1034 = On to inhibit output Y.
8. Latched step:
The On/Off status of the latched step will be memorized when the power of the PLC is switched off. When the
PLC is re-powered, the status before the power-off will be recovered and the execution will resume. Please be
aware of the area for the latched steps.
9. Special auxiliary relays and special registers: See 4.6refer to chapter 4.6 IST instruction for more details.
Device No. Function
M1040 Disabling step. Disabling all the shifting of steps when On.
M1041 Starting step. Flag for IST instruction.
M1042 Enabling pulses. Flag for IST instruction.
M1043 Zero return completed. Flag for IST instruction.
M1044 Zero point condition. Flag for IST instruction.
M1045 Disabling all output reset. Flag for IST instruction.