Digital input for toggling analog input polarity
Feature notes -
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Drive - CD series 5
Firmware - version 7.3.2
Firmware development - Aviv Halperin
Feature notes - Oren Kidron
©Copyright - Kollmorgen-Servotronix
3-Jan-2006
Abstract - This feature allows to
toggle polarity of the analog input using a digital input (INxMODE=32).
This can be used for commanding the drive in analog modes using separate
magnitude and direction command inputs.
Background - This feature was requested
following specific opportunity needs and has been included in the CD series 5
product development path.
Operation
details - One of the digital inputs is assigned to toggle the polarity of
the analog input (INxMODE=32). The analog
command itself is unchanged and is configured by setting the relevant parameters
for offset (ANOFF),
deadband (ANDB),
Filtering (ANLPFHZ) and
scaling (ISCALE, VSCALE depending on the
current/velocity mode).
Diagram -
analog input block diagram for analog velocity mode.
.tmp "Analog input diagram")
Example:
Task - an external control system has an analog
command of 0-5 Volts and a digital output for setting direction. It is desired
that the CD responds to velocity command where 5V corresponds to
2500rpm.
Application - Tune the CD
drive velocity controller (in serial mode), connect the digital command to CD
digital input 3 (for example), connect the analog command to user I/O analog
input.
Perform the following settings:
OPMODE=1;
analog velocity mode
IN3MODE=32;
activate the toggling feature
ANOFF=0;
analog offset, may need calibration (ANZERO)
ANDB=0;
analog deadband, effects behavior around zero
ANLPFHZ=500; Low
pass filter at 500Hz
VSCALE=5000; 10V
correspond to 5000rpm and 5V to 2500rpm.
More issues - When doing unipolar velocity
control with direction input, zero velocity crossing may need more attention.
Offset should be
calibrated (using the ANZERO mechanism) and analog deadband can be used
to ensure a quiet zero velocity
zone. Digital input is sampled in background and so 10-20msec delay should be
expected for the polarity toggle to occur
For more information please
contact:
Oren Kidron - Control Group - okidron@stx.kollmorgen.com
Avishai
zweig - Drive team - azweig@stx.kollmorgen.com