Installation manual

16
Epsilon EP-B Base Drive Reference Manual
Actual motor rotation direction will depend on pulse ratio polarity and setting of the Positive Direction bit.
Pulse Mode Parameters
The Pulse Position Input parameter shows the total pulse count received by the drive since the last power-up.
The Pulse Position Input, Position Command, Position Feedback Encoder and Position Feedback are initialized to zero
on power-up. Only Position Feedback Encoder can be pre-loaded serially with a value after power-up.
The Pulse Mode Ratio parameter includes a numerator which represents motor revolutions, and a denominator which
represents master pulses. The Pulse Ratio Revolutions is allowed to be negative which reverses all Pulse mode motion.
The Pulse Position Input is multiplied by the Pulse Mode Ratio to produce the Position Command.
Following Error/Following Error Limit
The Following Error is the algebraic difference between the Position Command and the Position Feedback. It is positive
when the Position Command is greater than the Position Feedback. All accumulated Following Error will be cleared
when the drive is disabled.
The Following Error Limit is functional in Pulse mode only. A Following Error Limit can be set using PowerTools Pro.
This limit is in motor revolutions and has a range of .001 to 10.000 revolutions. The Following Error Limit can be enabled
or disabled.
Pulse Mode Following Error
In Pulse Mode, the range of the Following Error is ±2863.3 revolutions. If the Following Error Limit is not enabled and
the Following Error exceeds 2863.3 revolutions, the displayed value is limited to this maximum value and will not rollover.
If the Following Error Limit Enable is enabled, the absolute value of the Following Error will be compared to the Following
Error Limit. If the limit is exceeded, a fault will be generated. If the Following Error Limit Enable is disabled, the Following
Error Limit is not used.
Velocity Mode Following Error
In Velocity mode, the maximum Following Error possible varies based on the gain and torque limit settings. When the
Actual Torque Command reaches the maximum possible level, the following error will stop increasing and any additional
position error will be dropped. In Velocity mode, when the following error exceeds the Following Error Limit parameter
there is no action.
Encoder Position and Position Feedback
Encoder Position and Position Feedback are two separate parameters which indicate the same physical motor position.
Encoder Position is the position change since power up in motor encoder counts and Position Feedback is the total
position change since power up in motor revolutions. The Position Direction parameter 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 Position parameter can be pre-loaded serially by setting the Position Feedback Encoder Modbus
parameter.
Analog Position Mode
Analog Position Mode Description
Analog position is an operating mode for the Epsilon EP-B drive. The drive receives an analog input signal and drives
the motor to a corresponding absolute position. The analog signal has a range of +/- 10 volts and is scaled to a motor
position in revolutions or other motor user units. An analog output on the drive can also be setup to provide an analog
output feedback signal.
An example of a basic analog position setup would be as follows: An input voltage of 0 volts can be setup to equal a
position of zero revolutions and a voltage of 10 volts can be setup to be a position of 10 revolutions. Therefore, if the
analog input signal on the drive reads 5 volts the position would equal 5 revolutions. An analog input signal of 10 volts
would equal 10 motor revolutions.
The analog position parameters can be setup using PowerTools Pro 4.0 software or can be taught by manually moving
the axis, setting the corresponding analog input and activating the “teach” input function.