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UVW - Encoder Connections
3.3.7 UVW Encoder
Interface X3A
The UVW encoder provides two differential analog channels for incremental
position and three analog channels for the absolute position of the motor.
Tracks A and B are incremental TTL signals with a maximum of 8,192
increments per revolution.
The zero track N track is not evaluated.
Tracks U, V, and W are absolute block commutation TTL signals.
The pole-pair number of the motor and encoder (the periods of the
UVW tracks) must be equal. If not, it may be possible to adjust the
number of UVW encoder commutation poles in LE13.
The order of the rising edge of the block commutation tracks must
be U, W, V with the reference being clockwise rotation as viewed from
the motor facing the encoder. If the encoder channels are specied to
have a different progression, then the corresponding channels must
be exchanged (e.g., if U, V, W = 1,2,3, then V+, V- and W+, W- channels
must be swapped).
40°
80°
10°
U
V
W
The levels of the U, V, and W signals are measured after switching on, and
thus the absolute position of the encoder is determined within an electrical
revolution of the motor (eg. revolution of the absolute tracks UVW). This
position can maximally vary with 30° of the electrical revolution. The current
position is rst set to this start position. If the motor starts to turn and the
rst rising edge at the U, V or W track is overdriven, the exact absolute
position is determined and the current position is corrected to this value.
Only the rising edge of the W track is evaluated for the position correction
during normal operation.
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