ST4200-50 Firmware Update
V3.03 Aug 17, 2026
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| Firmware (ST4200-50V303.zip) | |
|---|---|
| How to update (ST4200-50VUP_EN.pdf) |
○ The latest firmware version is available here.
○ Do not perform the following actions while the firmware is being updated, as this may require repair:
・Turn off the power to the unit.
・Remove the media.
○ If any issues arise as a result of the firmware update, please contact your nearest sales representative.
A USB flash drive is required for the firmware update. Please review the information above before downloading.
For update procedures, please refer to "How to Update."
"How to Update" describes the preparation steps and update procedure after downloading the firmware.
About the ST4200-50 Firmware
The current latest firmware version is as follows.
If you are using an older version, we recommend updating the firmware.
・Unit Firmware: V3.03
Version Upgrade History
V3.03 August 2026
Bug Fixes
・Fixed an issue where “Pre-measurement Voltage Adjustment”—one of the functions used to adjust the voltage applied to the test object during impulse PD measurements—would sometimes fail depending on the settings or individual device variations.
・Fixed an issue where screenshots were sometimes saved in a format different from the specified file extension. (Even if the file extension does not match the actual file type, the OS can still identify the contents and display them.)
Improvements
・We have addressed an issue where the screen would no longer automatically refresh when remotely controlling the ST4200-50 from a PC via a browser using recent browsers. (This was caused by changes to the PC browser’s specifications.)
V3.02 April 2026
Bug fixes
・Regarding AC PD calibration, if calibration is performed after initializing the settings (using the *RST communication command), it executes correctly. However, if calibration is performed without initialization, and the system is in an overrange state with a sensitivity of ×40 during calibration, incorrect calibration values are obtained.
This bug, which caused the PD measurement value (Qmax) to be an incorrect, larger value when measuring in this state, has been fixed.
・For impulse PD, RQpk should be the maximum value of Qpk in the pulse train generated by RPDIV, but it was set to the minimum value; this has been corrected to the maximum value.
・Fixed a bug where the AC PD measurement settings display screen (a screen that simply shows the current settings in one of the four divided sections) sometimes displayed items different from the ones selected.
V3.01 October 2025
Initial release