Rockwell Automation 1784-PM16SE SoftLogix Motion Card Setup and Configuration Manual - Manual (Page 386)

Publication 1784-UM003A-EN-P – June 2003
378 Motion Object Attributes
Drive Polarity
Custom Polarity
Custom Polarity is used to enable custom polarity configurations using the
various polarity parameters defined by the SERCOS Interface standard.
Positive/Negative Polarity
Positive and Negative Polarity bit attribute determine the overall polarity of the
servo loop of the drive. All the advanced polarity parameters are automatically
set based on whether the Drive Polarity is configured as Positive or Negative.
Proper wiring guarantees that the servo loop is closed with negative feedback.
However there is no such guarantee that the servo drive has the same sense of
forward direction as the user for a given application. Negative Polarity inverts
the polarity of both the command position and actual position data of the
servo drive. Thus, selecting either Positive or Negative Drive Polarity makes it
possible to configure the positive direction sense of the drive to agree with that
of the user. This attribute is configured automatically using the MRHD and
MAHD motion instructions. Refer to the Logix Motion Instruction
Specification for more information on these hookup diagnostic instructions.
GSV/SSV Access Attribute Name Data Type Values
GSV Drive Polarity DINT Enumeration:
0 = Custom Polarity
1 = Positive Polarity
2 = Negative Polarity