WIZ120SR corrupt


We are currently trialing the WIZ120SR module on a board utilising both serial ports.

We have the following problem with our module - can you please shed some light on the issue. Looks to be a memory problem and defaults are being loaded.

  1. Turn on power
  2. Search for device using application
  3. Device found with MAC 39:39:39:39:39:39
  4. Click on device and the following info shows
    Default serial info also shows (serial debugging disabled)
  5. I change any setting and click “Setting”
  6. Settings upload sucessfully
  7. Search for device again and device not found. Cannot contact with serial ports or application until reset of device but it resets to those default settings.


Steve Buhagiar

Hi, Steve.

I guess, this is the fault of manufacturing Processes(MAC write) or flash memory.

Do you have WIZ120SR-EVB?
If you have EVB, possible to re-write MAC Address.
If not, please RMA request to distributor.


Hi, can you please explain the process of re-writing MAC address or point me in the right direction for documentation. I could not find anything.



MAC address 39:39:39:39:39:39 is wrong.
So, i guess the WIZ120SR module’s state is ready to input the new MAC address.

Follow the next steps.

  1. The module connect to the PC and connect Terminal program.
  2. Turn on the module, terminal will print out “Wait for MAC address”.
  3. Input the MAC address as follows: S0008DCxxxxxx (refer to MAC address on your module)
  4. if the terminal program print out “R” and “OK”, input MAC address is success.