Rockwell Automation 1784-PM16SE SoftLogix Motion Card Setup and Configuration Manual - Manual (Page 309)

Publication 1784-UM003A-EN-P – June 2003
Motion Object Attributes 301
Hard Shutdown
When configured for Hard Shutdown, the axis is immediately placed in the
Shutdown state, i.e. Drive Enable disabled, Servo Action disabled, and the OK
contact opened. Unless the drive is configured to provide some form of
dynamic breaking, this results in the axis coasting to a stop. To recover from
the Shutdown state requires execution of one of the axis or group Shutdown
Reset instructions (MASR or MGSR).
Servo Status Attributes The following sections define in more detail the behavior of the various status
attributes associated with the Servo specific behavior of the Motion Axis
Object. Status attributes are, by definition, read access only. The following
Servo specific Status Attributes are divided into 3 categories: Servo Status
attributes, Servo Commissioning Status attributes, and Servo Status Bit
attributes.
Servo Status Attributes The list of Servo Status Attributes associated with the Axis Object provides
access to the servo module resident information for the axis. These values may
be used as part of the user program to perform real time measurements of
servo operation. A list of all Servo Status Attributes is shown in the tables
below.
Since Servo Status Attributes values are resident in the axis’ servo module,
these values need to be transferred to the ControlLogix processor module on a
regular basis. To avoid unnecessary communication traffic transferring data
that is not of interest, it is necessary to explicitly activate transfer of the
specific Servo Status Attribute data from the servo module using the Axis Info
Select attributes. Thus, a Servo Status Attribute value is ONLY valid if the
attribute has been selected by one of the Axis Info Select attributes. Otherwise
the Servo Status Attribute value is forced to zero.
In order for the position unit-based servo status attributes to return a
meaningful value, the ‘Conversion Constant’ Axis Configuration Attribute
must be established. Furthermore, attributes having velocity or acceleration
units (Position Units / Sec) must also have a valid coarse update period which
is established through association with a fully configured Motion Group
Object.
Each of the Servo Status Attributes appears in the following Servo block
diagram.