Control Techniques Digitax ST Advanced User's Manual page 49

Parameter Keypad and
structure display
Motor and load inertia
3.18
Bit SP
Coding
Range
0.00000 to 90.00000 kg m
Default 0.00000
Update rate Background (1s) read
The motor and load inertia represents the total inertia driven by the motor. This is used to set the speed controller gains (see Pr 3.13 on page 46) and
to provide torque feed-forwards during acceleration when required. (see Pr 4.11 on page 72) (It is possible to measure the inertia as part of the auto-
tune process, see Pr 5.12 on page 81.
Compliance angle
3.19
Bit SP
Coding
Range 0.0 to 359.9 °mechanical
Default 4.0
Update rate Background (1s) read
The compliance angle is the required angular displacement when the drive delivers a torque producing current equivalent to the current scaling (Kc)
with no field weakening.
Bandwidth
3.20
Bit SP
Coding
Range 0 to 255 Hz
Default 10 Hz
Update rate Background (1s) read
The bandwidth is defined as the theoretical 3dB point on the closed-loop gain characteristic of the speed controller as a second order system. At this
point the phase shift is approximately 60°. This parameter is used to define the bandwidth used for setting up the speed loop gain parameters
automatically when Pr 3.17 = 1.
Damping factor
3.21
Bit SP
Coding
Range 0.0 to 10.0
Default 1.0
Update rate Background (1s) read
This is the damping factor related to the response of the system to a torque transient, and so if the damping factor is unity the response to a load
torque transient is critically damped. The step response of the speed controller gives approximately 10% overshoot with unity damping factor.
This parameter is used to define the damping factor used for setting up the speed loop gain parameters automatically when Pr 3.17 = 1 or 2.
.
3.22 Hard speed reference
Bit SP
Coding
Range ±SPEED_FREQ_MAX rpm
Default 0.0
Update rate 4ms read
Digitax ST Advanced User Guide
Issue Number: 1
Parameter
Parameter x.00
description format
FI DE Txt VM DP ND
5
2
FI DE Txt VM DP ND
1
FI DE Txt VM DP ND
FI DE Txt VM DP ND
1
FI DE Txt VM DP ND
1 1
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Advanced parameter Serial comms
descriptions protocol
RA NC NV PT US RW BU
1 1
RA NC NV PT US RW BU
1 1
RA NC NV PT US RW BU
1 1
RA NC NV PT US RW BU
1 1
RA NC NV PT US RW BU
1 1
Electronic
Performance
nameplate
PS
1
PS
1
PS
1
PS
1
PS
1
Menu 3
49