Specifications

Principle of Operation
The DM960 resolver decoder provides an absolute multi-turn
encoder in conjunction with AVG Automation's RL210 series
multi-turn resolver, which has two resolvers: coarse and fine.
The fine resolver is driven directly from the RL210 shaft,
which in turn is directly coupled to the machine shaft. The
coarse resolver is coupled to the main shaft through a 64:1 or
128:1 gear train. The gear train uses an antibacklash precision
gear to assure full accuracy over the entire range. Thus the
coarse resolver makes one revolution for 64 or 128 turns of the
fine resolver. The coarse resolver counts the number of turns,
while the fine resolver keeps track of the position in the last
revolution and the two signals combined give absolute linear
position over multiple revolutions. As shown in the diagram,
the coarse and fine resolver rotor windings are excited from a
common reference sinusoidal generator. The resolver analog
output signals from the stator windings, after signal condition-
ing in the buffer amplifiers, are decoded to digital format in
two independent Ratiometric Tracking Converters. The digital
information from coarse (i.e., number of revolutions) and fine
(i.e., position in the last revolution) resolvers is then superim-
posed in the coarse-fine alignment circuitry to determine the
actual absolute position. The zero offset set by the front panel
thumbwheels is continuously added to this value and the
resultant position is, displayed on the front panel display. The
position information is also made available in a parallel format
for external devices such as PLC's remote displays etc.
Programmable Full Scale Offset for
Easy Set-Up
You can mount the resolver on the machine without any con-
cern for mechanically matching the resolver zero to the
machine zero. Once the resolver is coupled to the machine
shaft, the only thing you have to do is to bring the machine to
a known position, say home position, and set an offset number
using the front panel thumbwheel switches until the display
reads zero. Now the resolver zero is aligned with the machine
zero. This is especially useful during initial start-up in that it
reduces the set-up time. The offset can also be used to com-
pensate for any wear on the machine.
Variety of Outputs, Built-In PC-Handshake
Permit Interface to Any PLC
BCD, natural Binary, or Gray Code output formats are avail-
able with a choice of TTL, PNP (sourcing) transistor, or NPN
(sinking) transistor outputs. Optional PLC synchronization
circuit provides an error-free method of interfacing BCD posi-
tion data from the decoder to any PLC in the market. Upon
THE DM960
DM960 RESOLVER DECODER:
MULTI-TURN, SINGLE-CHANNEL
◆ Resolver-based, multi-turn, absolute position. No
loss of position under any situation
◆ Programmable full scale zero offset for easy set-up
◆ Variety of outputs, built-in PC-Handshake, permit
interface to any PLC
◆ Multiplexing capability
◆ High resolution; Up to 17-bits over total travel
◆ Highly noise immune ratiometric tracking
converter
◆ Extremely rugged and reliable resolver as a
position transducer
◆ Optically isolated outputs
800-TEC-ENGR
www.avg.net
A-30
Position Transducers/Sensors