Velocity Mode - Emerson Control Techniques Epsilon Eb Series Reference Manual

Epsilon Eb and EN Drives Reference Manual
setting will change which direction the motor rotates when the position feedback and position
command are counting up. In the default setting the position counts up when the motor shaft
rotates clockwise (when viewed from the shaft end).
The Encoder Feedback (Position Feedback Encoder) parameter can be pre-loaded serially by
setting the Position Feedback Encoder Modbus parameter.

Velocity Mode

Three submodes are associated with Velocity mode: Analog, Presets and Summation.
Analog Submode
The Analog Input receives an analog voltage which is converted to the Velocity Command
Analog parameter using the Full Scale Velocity, Analog Input Full Scale, and Analog Input
Zero Offset parameters. The equation for this conversion is:
((AI
=
VCA
Where:
VCA = Velocity Command Analog (RPM)
AI = Analog Input (volts)
AZO = Analog Input Zero Offset (volts)
FSV = Full Scale Velocity (RPM)
AFS = Analog Input Full Scale (volts)
The Velocity Command is always equal to the Velocity Command Analog in Analog
Velocity mode. The Velocity Command is the command received by the velocity closed loop
control.
Analog Accel/Decel Limit
This feature in the Analog submode allows you to limit the accel and decel rate when using
the analog input for velocity control. This makes it very simple to use the drive in high
performance, variable speed, start-stop applications such as Clutch-Brake replacements
without requiring a sophisticated controller to control the acceleration ramps. In applications
which do not require the drive to limit the ramps such as when using an external position
controller, the parameter can be set to "0" (its default value). If the Analog Accel/Decel Limit
parameter value is changed during a ramp, the new ramp limit is imposed within the next
servo loop update.
The Analog Accel/Decel Limit parameter is accessed on the Velocity tab. Its range is 0.0 to
32700.0 ms/kRPM.
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AZO) FSV)
AFS