Hitachi SJ Series, User Manual

Page: 443 / 786

12-24-12
Chapter 12 About the inverter function
Adding analog input [Ai3] to [Ai1] and [Ai2]
•
You
can forcibly add an input of the [Ai3] terminal
to [Ai1]/[Ai2].
(Example 4-1) [Cb-22]=01 (with reversibility)
Stabilizing signals of analog inputs
• To give a frequency instruction with an external
analog signal, you can set a sampling time for
voltage input or current input.
• This feature is effective for removing noise from
the frequency setting circuit.
• You are able to make an input of ±10 V to the
[Ai3] terminal. Use [Cb-22] to select whether the
output of reversibility for normal rotation or
reverse rotation is possible after making an
addition.
(Example 4-2) [Cb-22]=02 (without reversibility)
• Increase the set value if noise negatively affects a
stable operation. Note that the greater the set
value, the lower the responsiveness. When this
feature is used for a PID instruction, and a filter is
set, the filter would affect the feedback, and
therefore a fine operation would not be achieved.
Item Parameter Data Description
[Ai1] terminal input filter time
constant
[Cb-01] 1.~500.(ms) Sets a time constant for the input filter.
[Ai2] terminal input filter time
constant
[Cb-11] 1.~500.(ms) Sets a time constant for the input filter.
[Ai3] terminal input filter time
constant
[Cb-21] 1.~500.(ms) Sets a time constant for the input filter.
F(Ai1)
F(Ai2)
F(Ai2)+ F(Ai3)
0
AT
Nor
mal
Main
speed/auxiliary
speed instruction
[Ai1]/[Ai2] terminal
Addition
instruction
[Ai3] terminal
Actual frequency
instruction
F(Ai2)
0
0
F(Ai1)+ F(Ai3)
FW FW
SCHG
F(Ai2)
0
0
0
F(Ai1)
F(Ai2)
F(Ai1)+ F(Ai3)
F(Ai2)+
F(Ai3)
Rev
erse
Main speed/auxiliary
speed instruction
[Ai1]/[Ai2] terminal
Addition
instruction
[Ai3] terminal
Actual frequency
instruction
Nor
mal