Introduction to
Velocity Profiles
Getting Started
The SJ200 inverter is capable of sophisticated speed control. A graphical representation of that capability will help you understand and configure the associated parameters. This manual makes use of the velocity profile graph used in industry (shown at right). In the example, acceleration is a ramp to a set speed, and deceleration is a decline to a stop.
Speed | Set speed |
Accel Decel
0
t
Acceleration and deceleration settings specify | Speed |
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the time required to go from a stop to |
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maximum frequency (or visa versa). The |
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resulting slope (speed change divided by time) |
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is the acceleration or deceleration. An increase |
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in output frequency uses the acceleration | 0 |
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slope, while a decrease uses the deceleration |
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| Acceleration |
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slope. The accel or decel time a particular |
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| (time setting) |
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speed change depends on the starting and |
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ending frequencies. However, the slope is constant, corresponding to the
The SJ200 inverter can store up to 16 preset | Speed |
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speeds. And, it can apply separate acceleration |
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and deceleration transitions from any preset to |
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| Speed 1 | |||||
any other preset speed. A |
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(shown at right) uses two or more preset | 0 |
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speeds, which you can select via intelligent |
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input terminals. This external control can |
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apply any preset speed at any time. Alterna- |
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tively, the selected speed is infinitely variable across the speed range. You can use the potentiometer control on the keypad for manual control. The drive accepts analog
The inverter can drive the motor in either direction. Separate FW and RV commands select the direction of rotation. The motion profile example shows a forward motion followed by a reverse motion of shorter duration. The speed presets and analog signals control the magnitude of the speed, while the FWD and REV commands determine the direction before the motion starts.
Speed | Forward move |
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0 
t
Reverse move
NOTE: The SJ200 can move loads in both directions. However, it is not designed for use in