Mitsubishi Electric MELSEC-Q/L - Page 732

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7 APPLICATION INSTRUCTIONS
7.18 PID Instruction
• The setting items of the parameter (S3) are listed below.
*2 (S3)+20 to (S3)+24 are occupied when bit 1 of the action setting (ACT) in (S3)+1 = 1 and bit 2 = 1 or bit 5 = 1.
Setting item Description Remark
(S3) Sampling time (T
S
) 1 to 32767 ms The instruction cannot be used with a
value smaller than the operation cycle.
(S3)+1 Operation setting
(ACT)
Bit 0 0: Direct action
1: Reverse action
Specify the operation direction.
Bit 1 0: Disable alert for rate of change in input.
1: Enable alert for rate of change in input.

Bit 2 0: Disable alert for rate of change in output.
1: Enable alert for rate of change in output.
Do not set bits 2 and 5 to ON
simultaneously.
Bit 3 Unusable 
Bit 4 0: Disable auto tuning.
1: Enable auto tuning.

Bit 5 0: Disable upper and lower limit setting of output value.
1: Enable upper and lower limit setting of output value.
Do not set bits 2 and 5 to ON
simultaneously.
Bit 6 0: Step response method
1: Limit cycle method
Select the auto tuning mode.
Bits 7 to 15 Unusable 
(S3)+2 Input filter constant () 0 to 99% If 0 is specified, no input filter is used.
(S3)+3 Proportional gain (K
P
) 1 to 32767% 
(S3)+4 Integral time (T
I
) 0 to 32767  100ms Specifying 0 assumes . (No
integration)
(S3)+5 Derivative gain (K
D
) 0 to 100% Specifying 0 means no derivative gain.
(S3)+6 Derivative time (T
D
) 0 to 32767%  10ms Specifying 0 means no derivation.
(S3)+7 to
(S3)+19
Occupied for internal processing of PID operation, and therefore it is prohibited to change data.
(S3)+20
*2
Rate of change in input (increase side)
Alert setting value
0 to 32767  100ms Action direction (ACT): (S3)+1
Enabled when bit 1 = 1.
(S3)+21
*2
Rate of change in input (decrease side)
Alert setting value
0 to 32767 Action direction (ACT): (S3)+1
Enabled when bit 1 = 1.
(S3)+22
*2
Rate of change in output (increase side)
Alert setting value
0 to 32767 Action direction (ACT): (S3)+1
Enabled when bit 2 = 1 and bit 5 = 0.
Output upper limit setting value -32768 to 32767 Action direction (ACT): (S3)+1
Enabled when bit 2 = 0 and bit 5 = 1.
(S3)+23
*2
Rate of change in output (decrease
side) Alert setting value
0 to 32767 Action direction (ACT): (S3)+1
Enabled when bit 2 = 1 and bit 5 = 0.
Output lower limit setting value -32768 to 32767 Action direction (ACT): (S3)+1
Enabled when bit 2 = 0 and bit 5 = 1.
(S3)+24
*2
Alarm output Bit 0 0: Rate of change in input (increase side) not
exceeded
1: Rate of change in input (increase side) exceeded
Action direction (ACT): (S3)+1
Enabled when bit 1 = 1 or bit 2 = 1.
Bit 1 0: Rate of change in input (decrease side) not
exceeded
1: Rate of change in input (decrease side) exceeded

Bit 2 0: Rate of change in output (increase side) not
exceeded
1: Rate of change in output (increase side) exceeded

Bit 3 0: Rate of change in output (decrease side) not
exceeded
1: Rate of change in output (decrease side) exceeded

(S3)+25 PV value threshold (Hysteresis)width
(SHpv)
Set depending to the fluctuation of process value (PV). Action direction (ACT)
Bit 6: Occupied when the limit cycle
method (ON) is selected.
(S3)+26 Upper limit value of output (ULV) Set the maximum output value (ULV) of manipulated
value (MV).
(S3)+27 Lower limit value of output value (LLV) Set the minimum output value (LLV) of manipulated
value (MV).
(S3)+28 Wait setting parameter (K
W
) from the
end of tuning cycle to the start of PID
control
-50 to 32717%