We are using AL5D robot arms and the Flowarm PLTW software. When the arms are initially calibrated by the students and they record a sequence and save it. The next time they try to run that same sequence the calibration is off. Do they need to calibrate each time before running the saved program? Is there something that is not being saved correctly?
Hi,
The FlowArm PLTW software saves the calibration results in a local file. It has been a known issue that on some Windows setup (but not all), the user does not have rights to create a /write to a file in the folder where the settings would go.
The issue ends up being that instead of having an error message or something similar, Windows tries to be helpful by moving the calibration settings’ file to the “Virtual Store” where the user does have access.
Unfortunately, on start-up, the software tries to read the file from the proper folder (which the user typically has the rights for) and does not find the file, of course (and therefore no calibrations are loaded).
Since fixing the Windows setup/user rights issue is most certainly more complex, there is a simpler solution: have the calibration stored in the SSC-32U directly (i.e.: in the arm) instead! That way it gets stored in the EEPROM on the chip and never goes away.
The steps are quite simple:
- Download and install our free diagnostic tool, Lynxterm. You can obtain it here.
- Power the arm with its power supply (6 V DC > VS1) and connect it by USB.
- Start Lynxterm and connect to the arm. Once connected, press the All=1500 button at the bottom right to center all servomotors in each joint.
- Open the **Reg. **Read the data (pressing it twice is typically required) and calibrate the offset for each joint in the Offset column using the appropriate vertical slider.
- Make sure Global and Initial pulse offset are checked.
- Write the settings to the board. Confirm them by pressing Read afterwards.
- Your arm is not calibrated directly in the driver board. You will not need to calibrate it in software anymore. If you connect it to a FlowArm PLTW software/computer where calibration was performed in the past, you will need to remove the calibration file. Simply close the software and go to its installation folder (typically **Program Files (x86)\RobotShop\FlowArmPLTW_4**). The file is named “FlowArm PLTW 4.cal”. You can simply delete this file and start the software to be FlowArm calibration free.
For details about connecting with the arm using Lynxterm or performing the calibration, please see the two images below showing all the steps.
The SSC-32U should have a baud rate of 9600 by default. If it does not connect at that speed, you can confirm (and change) the baud rate of your SSC-32U by following the steps in the SSC-32U manual, page 34 (bottom half).
We hope this helps.
Sincerely,
