Advanced drive gain attributes, Drive limits, Maximum positive/negative travel – Rockwell Automation 1784-PM16SE SoftLogix Motion Card Setup and Configuration Manual User Manual
Page 406: Position error tolerance

Publication 1784-UM003A-EN-P – June 2003
398 Motion Object Attributes
Advanced Drive Gain Attributes
The above advanced attributes map directly to SERCOS IDNs. Thus, for a
detailed description of these attributes refer to the corresponding IDN
descriptions found in the SERCOS Interface standard or the AB SERCOS
Drive PISD. Since these attributes are automatically configured to reasonable
default values, manual configuration by the user is not required unless
motivated by a specific application requirement.
Drive Limits
This section covers the various drive attributes that either apply limits to
various servo loop real-time parameters, such as position and output voltage,
or are used in limit checks of servo loop parameters like position error.
Maximum Positive/Negative Travel
The Axis Object provides configurable software travel limits via the Maximum
Positive and Negative Travel attributes. If the axis is configured for software
overtravel limit checking by setting the Soft Overtravel Bit in the Drive
Configuration Bit word, and the axis passes outside these maximum travel
limits, a Software Overtravel Fault is issued.
When software overtravel checking is enabled, appropriate values for the
maximum travel in both the Maximum Positive and Maximum Negative Travel
attributes need to be established with Maximum Positive Travel always greater
than Maximum Negative Travel. Both of these values are specified in the
configured Position Units of the axis.
Note: The software travel limits are not enabled until the selected
homing sequence is completed.
Position Error Tolerance
The Position Error Tolerance parameter specifies how much position error the
drive tolerates before issuing a Position Error Fault. Like the position lock
tolerance, the position error tolerance is interpreted as a ± quantity.
GSV/SSV Access
Attribute Name
Data Type
Values
SSV/GSV
Velocity Droop
REAL
Position Units / sec.
GSV/SSV Access
Attribute Name
Data Type
Values
SSV/GSV
Maximum Positive Travel
REAL
Position Units
SSV/GSV
Maximum Negative Travel
REAL
Position Units
GSV/SSV Access
Attribute Name
Data Type
Values
SSV/GSV
Position Error Tolerance
REAL
Position Units