Parameter
structure
Keypad and
display
Parameter
x.00
Parameter
description format
Advanced parameter
descriptions
Macros
Serial comms
protocol
Electronic
nameplate
Performance RFC mode
Menus 15 to 17
SM-Resolver
Unidrive SP Advanced User Guide 275
Issue Number: 10 www.controltechniques.com
Pr x.04 and Pr x.05 give the position with a resolution of 1/2
16
ths of a revolution as a 32 bit number as shown below.
Provided the set-up parameters are correct, the position is always converted to units of 1/2
16
ths of a revolution, but some parts of the value may not
be relevant depending on the resolution of the feedback device. For example if 10 bit resolution is selected the resolver produces 4,096 counts per
revolution, and so the position is represented by the bits in the shaded area only.
When the feedback device rotates by more than one revolution, the revolutions in Pr x.04 increment or decrement in the form of a sixteen bit roll-over
counter.
The internal update time for the position Pr x.05 when used as feedback runs at level 1, this being switching frequency dependant as follows.
The internal update time for the speed Pr x.03 when used as feedback runs at level 2 as follows.
This parameter relates to the equivalent lines per revolution of a quadrature encoder that would provide same resolution of feedback. This parameter
should only be set to 256 (10 bit resolution), 1,024 (12 bit resolution) or 4,096 (14 bit resolution). If the parameter is set to any other value the drive
assumes the following: 32 to 256 = 256; 257 to 1,024 = 1,024; 1,025 to 50,000 = 4,096. If the drive is operating in Closed-loop vector or Servo modes
and the resolver is selected to provide speed feedback for the drive (see Pr 3.26) then variable maximum SPEED_LIMIT_MAX is defined in the
following table.
It should be noted that for a 2 pole resolver that this parameter defines the resolution over one mechanical revolution, but for a resolver with 4, 6 or 8
poles the resolution defines the resolution over an electrical revolution of the motor. For example with a 6 pole resolver (and 6 pole motor) the
resolution is over
1
/
3
of a mechanical revolution.
31 16 15 0
Revolutions Position
31 16 15 4 3 0
Revolutions
Position
Update time Switching frequency Level
167μs3kHz 1
125μs 4kHz, 8kHz, 16kHz 1
83μs 6kHz, 12kHz 1
Update time Switching frequency Level
250μs
3kHz, 4kHz, 6kHz, 8kHz,
12kHz, 16kHz
2
x.10 Equivalent lines per revolution
RW Uni US
Ú
0 to 50,000
Ö
4,096
Update rate: Background read
Resolver poles
(Pr x.15)
Equivalent lines per
revolution (Pr x.10)
Operating resolution
(bit)
SPEED_LIMIT_MAX
2 4,096 14 3,300.0
2 1,024 12 13,200.0
2 256 10 40,000.0
4 4,096 14 1,650.0
4 1,024 12 6,600.0
4 256 10 26,400.0
6 4,096 14 1,100.0
6 1,024 12 4,400.0
6 256 10 17,600.0
8 4,096 14 825.0
8 1,024 12 3,300.0
8 256 10 13,200.0
To Next Page
Loading...
Need help?
General
