Eaton ELC-PB, Programming Manual

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3 . I n s t r u c t i o n S e t
M N050 03003E F or mo re infor ma tio n vi sit:
w w w. e a t o n . c o m
3-255
Note2: The PID operation time without equation calculation (ELC-PB/PC/PA/PH/PV, ELCB-PB
about 44us) (ELCM-PH/PA approx. 8us)
Points to note:
1. There is no limit on the number of times the PID instruction can be used in a program, but the
addresses
S
3
~
S
3
+19 cannot be repeated.
2. For 16-bit instructions:
S
3
uses 20 registers. In the example below the parameter area of the
PID instruction for
S
3
is D100~D119.
3. Parameter table of 16-bit
S
3
:
Device No. Function Set-point range Explanation
S
3
: Sampling time (T
S
)
1~2,000
(unit: 10ms)
Time interval between PID calculations
and updates of MV. If T
S
= 0, the PID
instruction will not be enabled. If T
S
is
less than 1 program scan time, the PID
instruction sets
S
3
to 1 program scan
time, i.e. the value of T
S
cannot be less
than one program scan time.
S
3
+1: Propotional gain (K
P
) 0~30,000(%)
The proportion for minimizing the error
between SV and PV.
Integral gain (K
I
) 0~30,000(%)
The proportion for minimizing the
integral value (The accumulated error).
For control mode K0~K5.
S
3
+2:
Integral time
constant (T
I
)
0~30,000 (ms) For control mode K10
Differential gain (K
D
)
-30,000~30,000
(%)
The proportion for minimizing the
derivative value (The rate of change of
the process error). For control mode
K0~K5
S
3
+3
:
Derivative time
constant (T
D
)
-30,000~30,000
(ms)
For control mode K10
S
3
+4: Control method
0: Automatic control
1: Forward control (E = SV - PV).
2: Reverse control (E = PV - SV).
3: Auto-tuning of parameters exclusively for the
temperature control. The device will automatically
become K4 when the auto-tuning is completed and K
P
,
K
I
and K
D
are set with appropriate values (not avaliable
in the 32-bit instruction).