Operational Overview
In Torque mode the drive receives an Analog Input which is scaled to the Analog Torque Command by the Full Scale Torque, Analog Input Full Scale, and Analog Input Zero Offset parameters. The equation is:
TC = ((AI − AZO) FST)
AFS
Where:
TC = Torque Command
AI = Analog Input (volts)
AZO = Analog Input Zero Offset (volts)
FST = Full Scale Torque (%)
AFS = Analog Full Scale (volts)
Figure 73: Alternate Mode - Analog Torque Mode
Analog Torque Settings Group
Full Scale Torque
This parameter allows the user to scale torque in the drive to the analog input. Full Scale Torque = 10 Vdc.
Peak Torque Available
The Peak torque available parameter describes the peak torque available for the system, or the drive and motor combination based on the .ddf file.
Torque Mode Velocity Limiting Group
Velocity Limit Enable Check box
When this check box is selected, the Max Velocity and Hysteresis parameters are available in torque mode. This feature will stop the motor from "running away" when the torque is removed from the motor shaft.
Max Velocity
When operating in Torque Mode, this parameter represents the maximum velocity attainable independent of the torque on the motor shaft.
Hysteresis
When the Torque Velocity Limiting check box is selected, the drive will switch between Velocity Mode and Torque Mode depending on the speed of the motor. If the motor reaches the maximum velocity as specified by the Max Velocity parameter, the drive will switch into a constant Velocity Mode until the torque increases on the motor shaft bringing the motor speed down to the Hysteresis point. At this point the drive will switch back into Torque Mode until the Max Velocity point is reached again.
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