Rockwell Automation 20P PowerFlex Digital DC Drive - Manual (Page 293)

Rockwell Automation Publication 20P-UM001I-EN-P - February 2013 293
Application Notes Appendix C
Set the P gain for zero speed:
• If the P gain corresponds to the value set in Par 126 [Spd Zero P Gain],
then set Par 125 [Spd Zero P En] = 1 “Enabled”
• If the P gain corresponds to the normal P gain, then set Par 125 [Spd Zero
P En] = 0 “Disabled”
The P gain at zero speed is set via Par 126 [Spd Zero P Gain] when Par 125 [Spd
Zero P En] = 1 “Enabled”.
The threshold for the recognition of zero speed is determined by the value in Par
106 [Ref Zero Level].
Speed Draw Function
The Speed Draw function can be used to apply a configurable speed ratio (set in
Par 1017 [Speed Ratio]) to the main speed reference of the drive. This function is
useful in a multi-drive system where a proportional speed increase between the
motors is required. The range of parameter 1017 [Speed Ratio] can be set
between 0 and 32767 if written in digital form, or can be set from 0 to 20000 (0
to +10V) if assigned via an analog input. The resulting speed value can be viewed
in Par 1018 [Speed Draw Out] via an analog output.
Figure 83 - Speed Draw Example
M
Drive A
Master = 1000 RPM 1050 RPM 1100 RPM
+
Line Speed
M
Drive B
M
Drive C
+ +
Line Speed
ratio 1 = +5%
Anlg Input
1 Anlg Input
1 2 Anlg Input
1 2
Speed Ratio = 5.25V
(10500 count)
Line Speed
ratio 2 = +10%
Speed Ratio = 5.5V
(11000 count)