Table of Contents
Advertisement
4. PRESSURE LOOP GAIN ADJUSTMENT
4.4 Setting of pressure feedback
Execute setting related to the pressure feedback. Set the parameters of the load cell amplifier and the servo
amplifier.
(1) Setting of the pressure feedback unit constant
(a) Setting of the load cell amplifier
Adjust the voltage range of the load cell amplifier between 0 and +10 V according to the voltage
input range of the pressure feedback.
(b) Setting of [Pr. PT 22 Pressure feedback unit constant]
Set the conversion coefficient of the pressure feedback voltage to be returned to the controller in [Pr.
PT 22 Pressure feedback unit constant].
Set a pressure feedback value to be returned to the controller at the maximum input voltage (10 V)
of AD0 (Pressure feedback). For example, if [Pr. PT22] is set to "2000", the pressure is controlled in
a way the load cell voltage is 10 V when the controller gives the pressure command of 2000.
(2) Setting of the pressure feedback offset
(a) Setting of the load cell amplifier
When the load cell amplifier has an offset adjustment function, set the offset adjustment with the load
cell amplifier.
(b) Setting of [Pr. PT 21 Pressure feedback offset]
When the load cell amplifier does not have an offset adjustment function, set the pressure feedback
offset voltage with [Pr. PT 21 Pressure feedback offset].
When "100" is set, the voltage is compensated by -100 mV. When "-100" is set, the voltage is
compensated by +100 mV.
(3) Setting of the pressure feedback input filter
Set the low-pass filter for removing noise from the pressure feedback input. When the low-pass filter is
used, the filter response frequency affects the response performance of the pressure control. The higher
the filter response frequency, the more stable the pressure control with better response. The following
gives an indication of the filter response frequency.
Indication of filter response
Recommended: 500 Hz or higher
(2 ms or less)
Lowest: 100 Hz or higher
(10 ms or less)
(a) Setting of the load cell amplifier
If it is possible to set the low-pass filter as a noise removal function of the analog signal with the load
cell amplifier, set the filter with the load cell amplifier.
(b) Setting of [Pr. PT27 Analog monitor input filter setting]
If it is not possible to set the low-pass filter with the load cell amplifier, set the low-pass filter of the
pressure feedback by setting "AD0 (Pressure feedback) filter time constant" of [Pr. PT27] to "_ _ _
x".
frequency
Response performance of the pressure control is high, and the operation is stable.
When less than 100 Hz is set to increase the effect of noise removal, the pressure
control is still possible; however, the pressure control response will be low.
Explanation
4 - 3
Advertisement
Table of Contents
