Technology Option F01 08.2012
6SE7087-6QX70 (Version AN) Siemens AG
9-20 Compendium Motion Control SIMOVERT MASTERDRIVES
The absolute position of the resolver must match the mechanical
position of the flow axis. The alignment of the resolver is performed at
the factory and must not be modified. If you use a third-party motor with
a different alignment specification to a SIEMENS motor, the
displacement angle can be corrected with parameter P132.
If you use the SBR2 board, pulse encoder simulation is available on the
front connector. The number of pulses/revolution is configurable.
Depending on the parameter setting, the simulation produces 512 or
1024 pulses plus one zero pulse per revolution. This applies to the two-
pole resolver. Resolvers with larger numbers of poles output a
correspondingly higher number of pulses per revolution. The signals
are output as differential signals in pulse tracks displaced by 90°
(RS422) and are not potentially isolated.
Pulse Encoder Simulation
Par. Value
Meaning
P134 0
512 pulses per revolution
P134 1
1024 pulses per revolution
The two-pole resolver is the standard encoder.
If a multi-pole resolver has to be referenced, connector KK96 has to be
used according to Chapter 9.4.8 "Position sensing system for motor
encoder [330]".
9.4.5 Optical sin/cos encoder [240]
The resolution with an ERN1387 optical sin/cos encoder is represented
by the positional information of 2
24
= 16 777 216 graduations per
encoder revolution: for each 2048 sine and cosine periods per
revolution this yields a "rough digital resolution" of 8192 steps per motor
revolution after "pulse quadrupling" (evaluation of the zero crossings).
Each quarter period is resolved again into 2048 steps through the fine
analog amplitude evaluation of the sine/cosine signals.
The relative accuracy (repeatability) that can be achieved under
practical conditions is approximately 4 000 000 steps per revolution.
The system accomplishes high-precision position sensing with an
absolute accuracy of approximately 100 000...1 000 000 steps per
encoder revolution.
The sin/cos encoder uses a special sine/cosine track, each with one
period per revolution, to return the absolute position of the rotor from 0°
to 360°. Initial rough acquisition of the rotor position is undertaken when
the power is switched on, when moving out of the drive position (P60 =
5) or when fault F051 is acknowledged. This initial value is corrected
the first time the zero pulse is crossed, after which the full precision of
the encoder is available to the user.
Angle offset P132
Pulse encoder
simulation P134
Standard encoder
NOTE
Principle
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