Delta Electronics Programmable Logic Controller DVP-PLC - Manual (Page 391)

7 Application Instructions API 50-99
D V P - P L C A P P L I C AT I O N M A N U A L 7-107
API Mnemonic Operands Function
88 D PID PID Control Loop
Controllers
ES/EX/SS SA/SX/SC EH/SV
Bit Devices Word Devices Program Steps Type
OP X Y M S K H KnX KnY KnM KnS T C D E F
S
1
*
S
2
*
S
3
*
D *
PID : 9 steps
DPID: 17 steps
PULSE 16-bit 32-bit
ES EX SS SA SX SC EH SV ES EX SS SA SX SC EH SV ES EX SS SA SX SC EH SV
Operands:
S
1
: Set value (SV) S
2
: Present value (PV) S
3
: Parameter D: Output value (MV)
Explanations:
1. In 16-bit instruction, S
3
will occupy 20 consecutive devices; in 32-bit instruction, S
3
will occupy 21 consecutive
devices.
2. See the specifications of each model for their range of use.
3. See the Remarks below for the times of using PID instruction allowed in the program.
4. This instruction is specifically for PID control. PID operation will be executed by the scan only when the sampling
time is reached. PID refers to “proportion, integration and differential”. PID control is widely applied to many
machines, pneumatic and electronic equipments.
5. For the 16-bit instruction, the parameters are S
3
~ S
3
+19; for the 32-bit instruction, the parameters are S
3
~ S
3
+20.
After all the parameters are set up, PID instruction will start to be executed and the results will be stored in D. D
has to be the data register area without latched function. (If you wish to designate a latched data register area,
place the data register in the latched area at the beginning of the program and clear it as 0.)
Program Example:
1. Complete the parameter setting before executing PID instruction.
2. When X0 = On, the instruction will be executed and the result will be stored in D150. When X0 goes Off, the
instruction will not be executed and the data prior to the instruction will stay intact.
D150
X0
D100 D1 D0 PID
Remarks:
1. ES/EX/SS series MPU V5.7 (and above) supports PID instruction. Other versions do not support the instruction.
2. There is no limitation on the times of using this instruction. However, the register No. designated in S
3
cannot be
repeated.
3. For the 16-bit instruction, S
3
will occupy 20 registers. In the program example above, the area designated in S
3
is
D100 ~ D119. Before the execution of PID instruction, you have to transmit the setting value to the designated
register area by MOV instruction, If the designated registers are latched, use MOVP instruction to transmit all
setting value at a time.
4. Settings of S
3
in the 16-bit instruction