The diagram on the previous page
shows the cam table for a typical flying
shear application. It also shows the
expected shear velocity when the mas-
ter speed is constant.
Dual Loop: The dual-loop encoder fea-
ture enables the DMC-1700 to com-
pensate for backlash. There are two
compensation methods. The continu-
ous dual loop, which performs the cor-
rection along the move, and the sam-
pled dual loop, which performs the
correction at the final point.
In both cases two encoders are
used for each axis. One encoder is
mounted on the motor and one is
mounted on the load. The continuous
dual loop, which is activated with the
instruction DV1, closes the position
loop with the load encoder and derives
the damping terms from the motor
encoder. This method provides back-
lash compensation along the motion
path. The sampled dual loop performs
the correction at the end of the move.
Homing: The home (HM) command
can be used to home each motor to an
external mechanical reference and an
encoder index signal. The home speed
(SP) is programmable and the polarity
of the home switch is selectable using
the (CN) command. Alternative hom-
ing sequences can be created with the
FE and FI commands.
Sinusoidal Commutation: The
DMC-1700 is available with the sinu-
soidal commutation option. In this
mode, the controller performs a sinu-
soidal commutation of brushless
motors and outputs the sinusoidal
signals necessary to drive the motor
phases. This method allows the use
of low-cost amplifiers, thereby reduc-
ing the system cost.
The initialization procedure can
be customized for the users, accord-
ing to the available sensors such as
incremental encoders, hall sensors,
absolute encoders, or resolvers.
High Speed Latch: For precisely
sychronizing the position to an
external input, the high-speed latch
captures exact main or auxiliary
encoder position on the occurance
of an input. RL reports the latched
position.
High Speed Encoder Compare: The
OC command waits for an encoder
to reach a specified starting position
and then produces a pulse every
time the encoder passes a second
specified distance. This feature is
useful for triggering external events
to exact positions within .5
microseconds.
M O T I O N C O N T R O L L E R S
ISA BUS
DMC-1700
DMC-1700 ISA Bus Controller
19
DMC-1700 Series
5- thru 8-axis
