Servo motor torque mode test
Main idea[edit | edit source]
The servo motor torque mode test is a method to verify that basic parameters and wiring are correct. The target is to rotate/move the motor in torque mode in a continuous manner.
Assumptions[edit | edit source]
- All wiring are triple checked and torque tuning is done properly.
- Refer to the product user guidebook for detailed wiring instructions.
- Pay special attention to encoder operating voltage (VCC) and GND wiring. Wiring VCC and GND erroneously may damage the encoder.
- The motor is free to move/rotate, and no harm nor damages can happen from a long continuous movement.
- You have read and understood servo tuning basics.
|Don't use crossover cables in SimpleMotion V2 system|
Steps[edit | edit source]
|During this test, motor may spin at maximim speed. Ensure that motor is free to run, or if not, ensure that no damage occurs if it hits to mechanical limit.|
- Set the drive in Torque mode from Granity/Goals tab.
- Go to Granity/Testing tab.
- Make sure that the setpoint is zero and the drive is enabled and ready.
- Set the Target setpoint 1TSP1 Target setpoint 1 to 500.
- Increase the target setpoint slowly by clicking the "Increment by TSP1" button and checking whether the motor moves of not.
- When setpoint reaches 16384 or greater, the maximum current is being delivered to motor. So further increase of setpoint will not have any effect.
- If drive stops into overvelocity fault, it typically means that system works properly. However, you may increase Velocity tracking error thresholdFVT enough to complete the test without overvelocity fault.
- If the motor moves in a continuous manner, all parameters and wiring are correct.
- If the motor halts, click the "Set zero setpoint" button and follow the troubleshooting instructions below.
Troubleshooting[edit | edit source]
In most cases, the motor halts after a short movement if the feedback resolution is incorrect, or if it's direction is reversed.
- Check wiring, especially logic and motor voltages, Enable, and STO.
- Check [FBI] Invert feedback direction checkbox in Granity/Machine tab, and repeat the steps above.
- This inverts the encoder direction without the need for rewiring.
- Check the motor pole count and encoder resolution from their datasheets.
- Move the motor by known angle/distance, and check the position feedback reading from Granity/Testing tab.
- The Position feedback value in Granity/Testing tab is always in CPR (counts per revolution). From this, the correct PPR can be calculated for one revolution (PPR = CPR/4).
Further reading[edit | edit source]
After the torque mode is configured and the motor can be controlled in torque mode properly, velocity and/or position modes can be tuned. Please refer to their respective instruction pages for further details.