Rockwell Automation 8720MC Drives Integration Manual - Manual (Page 78)

Publication 8720MC-IN002A-EN-P — December 2002
4-4 SCANport Command Interface
The communication adapter allows the exchange of ten 16 bit
command input words to the drive from the PLC and ten - 16 bit status
output words from the drive to the PLC. SCANp_AN1_Value is the
parameter location (parameter 713) where the incoming velocity or
torque command value, as received from the adapter, is stored. When
either SCANport/DPI Spindle or SCANport/DPI Power Servo
applications are selected in parameter 501, all velocity, torque, and
logic commands are delivered to the 8720MC from the PLC via the
communication adapter on SCANport. SCANp_Analog_Out is the
parameter location (parameter 715) where the out going actual
velocity or torque value is stored.
SCANport_AN1_Value has a scaling factor associated with it as defined
in Appendix C. The default velocity scaling ±1 LSB = ±1 rpm. The
torque scaling is fixed at ±1000 = ±100% rated torque.
All velocity feedback or torque feedback and logic status information
is returned to the PLC from the 8720MC via the communication
adapter on SCANport. The drive can operate in position, velocity or
torque modes. The mode is determined by the primary operating
mode parameter for the active parameter set. There are 8 servo
parameter sets available to accommodate gear range switching, high /
low windings and mode switching. The active parameter set is stored
in parameter 254. Each parameter set has a primary operating mode
parameter. Refer to parameter 32 in Appendix C for a description of
the Primary Operating Mode Parameter. The SCANport adapter
reference command must be scaled by the PLC if something other
than the default scaling is required. The default velocity scaling ±1
LSB = ±1 rpm. The torque scaling is fixed at ±1000 = ±100% rated
torque
SCANport Command Logic Inputs
When SCANport is the primary command interface the velocity or the
torque command is provided from an Allen-Bradley PLC via a
SCANport adapter. The key logic commands are passed through the
Logic Input Command Word and the Logic Output Status Word. The
following descriptions apply:
Regenerative Stop Request - When this bit is set true by the PLC the
drive will come to a regenerative stop regardless of the auto or jog
reference command.
Start Request - When the start command bit is set true and there are
no faults the drive will respond to the auto reference in auto mode
and the jog reference in manual mode. It will continue to follow the
reference until there is a regenerative stop or a coast stop request or
the active reference is set to zero.