Chapter 4
CIP Axis Attributes
254
Rockwell Automation Publication MOTION-RM003I-EN-P - February 2018
No explicit action is taken by the device in the overload condition if None is the
selected overload action. Selecting the Current Foldback action, however, results
in a reduction of the inverter current in proportion to the percentage difference
between Inverter Capacity and the Inverter Overload Limit, or in the case of the
I
2
T overload protection method, in proportion to the difference between the
inverter current, in percent of rated continuous inverter current, and the Inverter
Overload Limit.
If an inverter overload condition occurs due to the power block thermal model,
two additional overload actions can be applied. Selecting Reduce PWM Rate can
be used to reduce heat generated by switching losses in the inverter power
structure. When PWM - Foldback is selected the device first reduces the PWM
rate and then, if necessary, reduces the Inverter Thermal Current Limit.
See also
Power and Thermal Management Status Attributes
These are the power and thermal status related attributes associated with a
Motion Control Axis.
Motor Overload Protection Method
Usage
Access
T Data
Type
Default
Min
Max
Semantics of Values
Optional - BD
Get/GSV
T USINT
-
-
-
Enumeration:
0 = Thermal Model
1 = I
2
T Overload
The Motor Overload Protection Method attribute is an enumerated value
indicates what motor overload protection method is being used by the CIP
Motion device.
Thermal Model motor overload protection applies the measured motor current to
an internal motor thermal model to detect a motor overload condition.
I
2
T Overload motor overload protection applies an I
2
T calculation once the motor
current exceeds the product of the Motor Overload Limit and the Motor Rated
Continuous Current that indicates a motor overload condition.
Inverter Overload Protection Method
Usage
Access
T Data
Type
Default
Min
Max
Semantics of Values
Optional- BD
Get/GSV
T USINT
-
-
-
Enumeration:
0 = Thermal Model
1 = I
2
T Overload
Power and Thermal
Management Status Attributes