KC901C+/KC901S+ Firmware Download

KC901C+ and KC901S+ are equipped with firmware upgrade function, you only need to deposit the ROM package into the TF (micro SD) card and follow the instructions to complete the upgrade without other settings.

1. Applicable version

All versions of the publicly available KC901C+ and KC901S+ support firmware upgrades.

The maximum supported TF card capacity is 32GB with FAT32 file system. Large capacity TF cards may have compatibility issues, smaller capacity cards (under 4GB) hardly have compatibility issues.

The upgrade packages for the 901C+ and 901S+ are the same, and the firmware will automatically recognize the hardware model. The upgrade package names are both 901SPRom.bin.

2. ROM Pack Download

Version 1.2.9, released August 6, 2023.

This update mainly maintains the remote control function. If you need to use the remote control function, please make sure to upgrade; if you only use it locally, you can not upgrade.

Fixes: 1. In remote control state, if S21 function is used, functions such as SPEC and S11 can no longer be enabled; 2. In remote control state, part of the calibration data is wrong; 3. In remote control state, if the frequency is lower than 60MHz, the S11 data is abnormal; 4. In remote control state, if S11 is enabled for calibration, part of the data is wrong.

Modification or addition: The return of real-time alarm data is canceled and changed to active query by the upper computer to avoid the alarm interfering with the measurement; the remote operation function of S21 group delay measurement is added. See the latest version of the programming manual for details.


Version 1.2.8, released October 15, 2022.

Fixes: the problem of failing to store files when scanning at 3150 points under the Smith display mode of S11 test; the problem of incomplete display of certain characters under the signal source function; the problem of crashing under certain operations when adjusting the speed coefficients in the DTF interface; the problem of errors in the VSWR data returned to S11 under the remote control mode.


Version 1.2.3, released March 3, 2021.

Fix:S21 Loss mode, when the number of scanning points is larger than 450, the reading file is abnormal; the upper computer will return an error once after receiving commands for a long time; the consistency between positive and negative cable length and cable attenuation; Optimization: the cable length can be set as a negative number.