Installation manual

Danaher Motion Kollmorgen 08/04 Wiring
SERVOSTAR S Installation M-SS-001-01 Rev. T 35
4.9.2.2. Cable Lengths
It is important to use properly shielded cable and to keep it away
from other noise-radiating devices and cables. It is not
recommended to run the feedback and motor cables in the same
conduit. Danaher Motion has tested cable lengths up to 75 ft. (22.9
m). without degradation of performance. Performance may vary,
however,depending on motor and resolver type. Tests were
performed with a standard low-impedance Danaher Motion cable
and Danaher Motion
GOLDLINE motor resolver. Please contact
Danaher Motion for cable and resolver impedance specifications
when long cable runs above 250 ft. (76 m) are desired. Danaher
Motion recommends twisted-shielded pair for feedback cables.
4.9.2.3. Resolution and Accuracy
The SERVOSTAR calculates motor velocity as the derivative of
position (change in position over time). With its patented technique,
all readings are extended to a resolution of 16-bit. For velocity
feedback calculations the drive converts the resolver input to 18
bits of resolution, giving smooth motor velocity control. The digital
resolution (RDRES) of the Resolver-to-Digital Converter system is
determined automatically according to the application velocity limit
(VLIM). The following is a summary of the SERVO
STAR’s
resolution capabilities:
R/D Converter Specifications
VLIM (RPM) RDRES Counts/Rev Encoder Eqv. Output (C4)
> 6100 12 4096 4096 quad counts
1500 to 6100 14 16384 16384 quad counts
< 1500 16 65536 65536 quad counts
System accuracy using resolver feedback is affected by several
components. Resolver Accuracy Specifications gives information
on the inaccuracy that each of these components contribute to the
total accuracy of a standard SERVO
STAR system:
Resolver Accuracy Specifications
Components ArcMinutes
R/D Converter 4
Resolver mechanics (rotational) 8
Resolver mounting on motor shaft 2
Inter-LSB (digital dither over the least
significant bit)
5
Total (Worse-case) 19