Hitachi SJ Series User Manual page 267

Chapter 12
Output of ± switching PID1 deviation
A
• Output is feasible by switching ± PID1 deviation.
• When PID1 deviation minus [AH-02] is 00,
calculation will be performed by (PID target value -
FB value). With 01, it will be the same operation as
(FB value - PID target value).
• Use this when the polarity of deviation of PID target
value and FB value does not much with the
command from the inverter due to sensor
characteristics, etc.
PID target value
Feedback data value
PID1 feed-forward value selection
Ａ
• Select PID1-feed forward value.
Analog input Ai1 to Ai6 (01 to 06)
e.g.) Control the compressor for refrigerator.
When the temperature sensor specification is -20
to 100°C: 0 to 10 (V) and the target value is 0°C,
and if the current temperature is 10°C, the speed
will decrease in normal PID control as it is (FB
value) > (PID target value).
• The inverter will raise the speed if [AH-02] = 01 is
set.
PID1 deviation
minus 1
[AH-02]
+
00
-
01
×(-1)
• Feed-forward control operates by setting [AH-70] to
anything other than 00 (None).
Input
destination 1
[AH-70]
(00~06)
01
(00: Disable)
12-10-12
Inverter Functions
[db-51]
PID calculation
[db-64]
PID feed-forward value