## Digital input for toggling analog input polarity

Feature notes - ####

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.
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