Hitachi L100-004 HFE Manual page 51

Function Display
(Continued from previous page)
control is not used, in this case it is really the set value that gets adjusted. So when the PID control is activated, the
functions A 11 through A 14 do not adjust the set value but the actual value instead).
f
A 12
A 15 = 00
A 11
A 15 = 01
A 13 A 14
0V
4mA
The parameters of functions A 11 through A 14 are changed from Hz to % due to the PID control's activation (done
using A 71) and to engineering units by setting function A 75. For this reason, function A 71 must be set to 01 before
the other functions are configured.
Displayed values
Function d 04 enables the display of the actual value while F 01 enables the display of the set value. These values can
be displayed in engineering units by setting function A 75.
When function F 01 is activated the PID set value will be displayed, but there is no permanent update of the displayed
value. When function d 04 is activated the actual value will be displayed which in contrast to the set value does get
permanently updated.
P, I and D gain
Although these gains can be set independently of each
other, there are interactions between them. When the P
gain (k ) is changed, the effective I gain changes (T
p
also. Only when k = 1, the effective I gain (T
p
to the I gain that had been entered (T
equal to 1, T can be calculated as follows:
N*
T = T * k (refer to the figure on the right).
p
N* N
PID block diagram
Set value (set under A 01):
- Digital operator pot
- Entry using F 01
- Terminal O or OI
- Multistage frequencies
Set value input:
settable using A 76
(terminals O or OI)
PID control
A 71
active / not active
P (proportional) gain
A 72
of PID control
I (integral) gain
A 73
of PID control
D (differential) gain
A 74
of PID control
Scale conversion
A 75
of PID control
Feedback signal
A 76
location
Function description / parameter setting range
)
*
x axis:
Voltage or current actual value into analog input (when PID control is used)
Voltage or current set value into analog input (when PID control is not used)
10V
20mA
)
N*
) is equal
N*
). When k is not
p
N
Analog set value adjustm.
A 11 through A 14
00: PID control is not used (not active)
N
01: PID control is used (active)
The proportional gain of PID control can be set in the range of
Y
0.2 through 5.0.
The integral gain of PID control can be set in the range of 0.0s
Y
through 150s.
The differential gain of PID control can be set in the range of 0.0s
Y
through 100s.
The set value or actual value to be displayed on the LED display can
be multiplied by a factor in the range of 0.01 through 99.99 so that
N
engineering units (e.g. flow or throughput) can be displayed instead
of the frequency.
The set value can be fed into one of two different analog inputs:
00: analog input OI
N
(The set value can also be set using the potentiometer or the multistage
frequencies).
8-8
Chapter 8 – Using the digital operator
Control output
jump response
0
T
N*
T
N
A 75
P
A 72
+
+
I +
A 73
-
+
D
A 74
01: analog input O
Standard
setting
T : Set readjustment
N
time (kp = 1)
T : Effective readjust-
N*
ment time (kp = 0,5)
t
F 01
Output frequency
Monitor
A 75
d 04
00
1.0
1.0
0.0
1.00
00