Setting up a vfd jog function and configuring a vfd s-curve profile are daily tasks on our production test floor. When I walk the assembly line at SHZK, the most common commissioning questions from our clients revolve around fine-tuning these exact motion profiles. Whether you are positioning a conveyor or smoothing out a heavy fan start, getting the SHZK 300N series parameters right prevents mechanical shock and optimizes cycle times. A standard variable-frequency drive handles basic speed control, but mastering these auxiliary and start/stop parameters is what separates a basic installation from a highly optimized machine. Let’s look at the exact P-group parameters we use during factory acceptance testing.
Configuring VFD Jog (Click-to-Run) Parameters
On the SHZK 300N, the jog function is labeled ‘Click-to-run’. This is incredibly useful for manual positioning during machine setup or maintenance. We wire the digital inputs on the terminal block to trigger this mode directly from the control panel or external buttons.
The core parameters live in the P8 group. P8-00 sets the click-to-run frequency, defaulting to 6.00 Hz. You can push this up to the maximum frequency, but for safety during manual jogging, we usually keep it under 10 Hz. P8-01 and P8-02 define the acceleration and deceleration times specifically for this jog mode. Both default to 20.0 seconds, with a massive range up to 6500.0 seconds. If your load has high inertia, increase these times to prevent overcurrent faults when you release the jog button.
Implementing VFD S-Curve Start and Stop
Linear ramps are fine for small pumps, but heavy conveyors and hoists need a smoother transition. This is where the vfd s-curve feature saves your mechanical components. By modifying the acceleration profile, we eliminate the initial jerk (j-factor) and the final snap.
To enable this, change P6-07 from its default of 0 (Linear) to 1 (S-curve A) or 2 (S-curve B). Note that the simplified motherboard M41H1 does not support items 1 and 2; it only runs linear ramps. Once enabled, P6-08 and P6-09 shape the curve. P6-08 sets the proportion of the initial phase duration (default 30.0%), and P6-09 sets the proportion of time at the end of the curve (default 30.0%). The sum of these two cannot exceed 100%. Understanding these motion profiles helps you tune the drive for delicate loads without needing external PLC motion control modules.
Setting Up Multiple Accel/Decel Times
Sometimes a single ramp time doesn’t fit the entire process. You might need a fast ramp to reach full speed quickly, but a slow, controlled ramp when stopping to prevent water hammer in a piping system. The SHZK 300N gives you up to four independent ramp pairs.
While P0-11 and P0-12 handle your primary ramp times, the auxiliary ramps are tucked into the P8 group. P8-03 and P8-04 control Acceleration and Reduction Time 2. P8-05 and P8-06 handle Time 3, while P8-07 and P8-08 manage Time 4. All of these accept a range from 0.0s to 6500.0s. You map these to your digital inputs via the terminal function codes. On the test bench, we frequently use Ramp 2 for a slow, safe stop during maintenance mode. When communicating these multi-ramp commands over a network, ensuring your Modbus RTU mapping is correct prevents the drive from ignoring the secondary ramp triggers.
Quick Parameter Reference
| Parameter | Function Name | Set Range | Factory Default |
|---|---|---|---|
| P6-07 | Accel/Decel Methods | 0: Linear, 1: S-curve A, 2: S-curve B | 0 |
| P6-08 | S-curve Initial Phase Proportion | 0.0% ~ (100.0% – P6-09) | 30.0% |
| P6-09 | S-curve End Phase Proportion | 0.0% ~ (100.0% – P6-08) | 30.0% |
| P8-00 | Click-to-run (Jog) Frequency | 0.00 Hz to max frequency | 6.00 Hz |
| P8-01 | Jog Acceleration Time | 0.0s ~ 6500.0s | 20.0s |
| P8-02 | Jog Deceleration Time | 0.0s ~ 6500.0s | 20.0s |
| P8-03 | Acceleration Time 2 | 0.0s ~ 6500.0s | Model Selection |
| P8-04 | Reduction Time 2 | 0.0s ~ 6500.0s | Model Selection |
| P8-05 | Acceleration Time 3 | 0.0s ~ 6500.0s | Model Selection |
| P8-06 | Reduction Time 3 | 0.0s ~ 6500.0s | Model Selection |
| P8-07 | Acceleration Time 4 | 0.0s ~ 6500.0s | Model Selection |
| P8-08 | Reduction Time 4 | 0.0s ~ 6500.0s | Model Selection |
Need Application Support?
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