Siemens SIMATIC FM 453, Manual

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9-67
FM 453 Servo Drive / Step Drive Positioning Module
C79000-G7076-C453-01
9.6.3 Stepper Motor Without Encoder
The FM 453 also operates with stepper motors without encoders.
The position resolution of the axis is determined by the traversing distance of
one motor increment.
The control frequency pulses emitted by the FM 453 are added internally to
form a position value.
The following table shows you how to adapt a stepper motor to the FM 453.
MD Designation Value/Meaning Comments/Unit
11 Travel per motor revolution
(division period)
1...1,000,000,000
see Section 5.3.1,
Dependencies (MSR)
(integer portion)
12 Residual distance per motor
revolution (division period) 0...2
32
–1
see Section 5.3.1,
Dependencies
(2
–32
MSR)
(fractional portion)
52 Increments per motor revo-
lution (division period)) 4...10 000 Entry per stepper mo-
tor data plate
MSR stands for measurement system raster (see Section 5.3.1)
Stepper motor: Number of increments per revolution (MD52) = 10,000
Machine design:
Motor with 50:30 gear ratio on spindle with 10 mm pitch = 10,000 MSR
From this one can calculate the following traversing distance per motor revo-
lution:
Travel per motor revolution =
50 spindle revolutions
30 motor revolutions
i 10,000 MSR = 16,666.666... MSR
Gear ratio: i =
= 1.666666...
The following values are entered:
MD Value Unit
11 16 666 (10
–3
mm)
12 0.666... 2
32
= 2,863,311,530 (2
–32
10
–3
mm)
13 2 500 (pulse/rev)
Overview
Function
Parameters
Example for
Stepper Motor
Adjustment
Description of Functions