Initial State - Delta DVP-PLC Applications Manual

API Mnemonic
60 IST
Type Bit Devices
X Y
OP
S * *
D
1
D
2
Operands:
S: Start device in the designated operation mode
: The biggest No. of designated step in auto mode
D
2
Explanations:
1. S will occupy 8 consecutive points.
2. Range of D and D : for SA/SX/SC/EH/EH2/SV S20 ~ S899; for ES/EX/SS S20 ~ S127; D
1 2
3. See the specifications of each model for their range of use.
4. ES/SA series MPU does not support E, F index register modification.
5. IST instruction can only be used once in the program.
6. Flags: M1040 ~ M1047. See remarks for more details.
7. IST instruction is a handy instruction specifically for the initial status of step ladder control procedure to
accommodate special auxiliary relay.
Program Example 1:
1. Use of IST instruction
M1000
IST
X10: Individual operation
S
X11: Zero return
X12: Step operation
X13: One cycle operation
2. When IST instruction is being executed, the following special auxiliary relays will switch automatically.
M1040: Operation forbidden
M1041: Operation starts
M1042: Pulse output enabled
M1047: STL monitor enabled
3. S10 ~ S19 are for zero return and cannot be used as general steps. When S0 ~ S9 are in use, S0 ~ S2 represent
manual operation mode, zero return mode and auto operation mode. Therefore, in the program , you have to
write the circuit of the three steps in advance.
4. When switched to S1 (zero return) mode, any On in S10 ~ S19 will result in no zero return.
5. When switched to S2 (auto operation) mode, any On of the S in D
operation.
D V P - P L C A P P L I C AT I O N M A N U A L
Operands
M S K H KnX KnY KnM KnS T
*
*
*
ES EX SS SA SX SC EH SV ES EX SS SA SX SC EH SV ES EX SS SA SX SC EH SV
X10 S20 S60
X14: Continuous operation
X15: Zero return enabled switch
X16: Start switch
X17: Stop switch
S0: Initiates manual operation
S1: Initiates zero return
S2: Initiates auto operation
7 Application Instructions API 50-99
Function

Initial State

Word Devices
C
PULSE
: The smallest No. of designated step in auto mode
D
1
~ D
1
Controllers
ES/EX/SS SA/SX/SC EH/SV
Program Steps
D E F IST: 7 steps
16-bit
> D
2
or M1043 = On will result in no auto
2
32-bit
.
1
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