Frequently Asked Question
Why the Virtual Serial Port (VCOM) on CipherLab 3656 (Bluetooth Transponder) refreshes continuously, and the PC cannot receive the data?
Last Updated 3 months ago
When your 3656 uses an old bridge kernel firmware such as v1.02, it is not compatible with the latest Silicon Labs USB VCOM for Windows Driver such as v6.7. The table below shows what version of Silicon Labs USB VCOM for Windows Driver can be supported by specific 3656 firmware version.
| Firmware version | Supported Silicon Labs USB VCOM for Windows Driver version |
| 3656 bridge kernel firmware version 1.03 | v5.4.24 to v6.6.1 |
| 3656 bridge user firmware version 1.07 | up to v6.7 |
If you encounter this issue, it means your Silicon Labs USB VCOM for Windows Driver is new, but the 3656 bridge kernel and user firmware are old. Please follow steps below to solve this problem.
Step1.
Downgrade the Silicon Labs USB VCOM for Windows Driver version to v5.4.
Step2.
Now you can transfer data through 3656 between a scanner and a PC. You can test it by scanning barcodes. Then you can upgrade the 3656’s firmware.