Emerson P/N 400518-02 manual Motor Parameter Descriptions, Motor Poles, Motor Encoder Marker Angle

Epsilon EP-I Indexing Drive and FM-2 Indexing Module Reference Manual

encoderMarker=330

encoderU=330

encoderRef=0

rotorInertia=0.00017

motorKE=28.3

phaseResistance=7.30

phaseInductance=12.5

peakCurrent=7.80

continuousCurrent=2.60

maxOperatingSpeed=5000

In this example, the parameters of two user defined motors are named “User1” and “User2”. Abbreviated parameter identifiers are used in the .ddf file. The table below shows the abbreviated identifier for each parameter followed by a description of each.

Motor Parameter	DDF Identifier
Motor Poles	motorPoles
Motor Encoder Lines Per Revolution	encoderLines
Motor Encoder Marker Angle	encoderMarker
Motor Encoder U Angle	encoderU
Motor Encoder Reference Motion	encoderRef
Motor Inertia	rotorInertia
Motor KE	motorKE
Motor Resistance	phaseResistance
Motor Inductance	phaseInductance
Motor Peak Current	peakCurrent
Motor Continuous Current	continuousCurrent
Motor Maximum Operating Speed	maxOperatingSpeed

Motor Parameter Descriptions

Note

These parameters are valid and active only when a user defined motor is selected. When a Control Techniques motor is selected, the data in these registers remain at the last value set and do not update to reflect the data of the Control Techniques motor selected.

Motor Poles

Specifies the number of magnetic pole pairs (N-S) on the motor. The supported values are 2, 4, 6, 8, 10, 12, 14 and 16 poles.

Motor Encoder Lines Per Revolution

Specifies the number of encoder lines per mechanical revolution. The supported values are 1000, 1024, 2000, 2048, 2500, 4096 and 8192. The number of “encoder counts” per revolution is 4 times the value specified here because quadrature decoding is used.

This parameter is used both for commutation and for position/ velocity control. To properly commutate the motor, the drive must know the electrical angle (the angle between the motor magnetic field and stator coils).

Motor Encoder Marker Angle

Specifies the electrical angle at which the marker (Z) pulse occurs with reference to VTS when the motor is spun in the encoder reference direction. At power-up the drive obtains an initial estimate of the electrical angle from the status of the U, V and W commutation tracks. This estimate can be off by as much as 30 °.

When the drive receives the marker pulse, the drive will, within one second, gradually shift the commutation to the more accurate electrical angle specified by this parameter. The system will then operate more efficiently. See “Step 3: Determine Encoder Alignment” for a detailed procedure on how to determine this parameter.

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