WIZ108SR data lost at 115.2 Kbps with new firmware

I have several WIZ108SR modules which I use in RS-422 mode with settings as follow:

  • COM port settings:
  • Baud Rate(R): 115200
  • Data Bit(D): 8
  • Parity(P): NONE
  • Stop Bit(S): 1
  • Flow Control(F): NONE

Serial data packing condition settings:

  • Timer(T): 0
  • Size(Z): 0
  • Character(C): 0

Serial command mode switch code:

  • Disable

Only those with firmware version 3.11 are able to work at 115.2 Kbps without data lost. All other newer firmware works only up to 57.6 Kbps no matter what Serial data packing condition settings values.

Could someone else confirm this, please?

Hi XFiles.
We are updated new version firmware for WIZ107/108SR. (v4.04)
It is the bug fixed version: data loss problem, DHCP lease time checker.

The new firmware has not been updated yet but it will be updated soon at our website.
I’ve attached WIZ108SR v4.04 firmware in this post for you.
Please try updated your module using this firmware.
(This firmware version for HW Rev.1.2 / 1.4 only. not WIZ108SR HW Rev 1.1)

WIZ108SRv4_04.zip (21.4 KB)


Hi hkjung,

Thank a lot for your reply. I have upgraded and tested one of my WIZ108SR modules with your new firmware (v4.04). Everything seems to work properly now at 115.2Kbps. I’ll continue the test for a few more days to see how it performs with various other settings.

Thank again for your excellent service.

I am having a similar issue using v4.04. We are using the same serial configuration. We have a high occurrence of characters with 1010 binary configuration getting dropped. Is the 57600 baud rate significantly more stable? Stability is a primary concern for our application.

Hi, bbaker.
Our v4.05 firmware for WIZ108SR was released.
Please use the latest version. The latest firmware can be found at the following link:

Yes. If the product is operating at low baud rate can be more stable because it uses a finite buffers.