WIZ750SR: Problem using in serial command mode

Hi there,

WIZ750SR (PCB Ver1.2; FW Ver1.3.3) has been working fine and I am able to change configuration like IP, Gateway, Port# etc via “WIZnet S2E Configuration Tool v1.3.0”.

In my application, I want to change the configuration parameters through W7500P data port.

I have enabled the serial command mode with default trigger code “+++”.

I am using Hercules setup utility software in my PC for seeing/sending the data on both ends, ethernet as well as Serial.

I can see the data being forwarded to other end is fine. Like, if I transmit any character through serial, I can read it on ethernet side and vice-versa.

For switching the device W7500P in command mode, when I send “+++” on serial, the ethernet link breaks immediately and the device is switching to command mode or ATMODE (verified through “WIZnet S2E Configuration Tool v1.3.0”). But after that I am not able to get any response for any command being sent through serial port.
e.g. command “MA$0d$0a” returns nothing.

I am referring to command manual link: Command Manual-[EN] | WIZnet Document System

Thanks in advance for your time.

Harish KS

MA & PW is a command that acts as a kind of header when sending commands through Ethernet.
They are not used in serial command mode.

How about other commands like MC, VR, LI?
If you entered ATMODE normally, there should be a response.

Hi Rena,

  1. I am sending commands on the data port, i.e. RS485 pins of WIZ750SR-RS485 (J1’s Pin 3&5).
  2. I am using Hercules windows software for connection to board for both ends (Ethernet and RS485).
  3. Upon sending the “+++”, TCP connection get closed as expected and also, while I see in S2E config software the status changes from “OPEN” to “ATMODE”.
  4. After getting into ATMODE, when I send “MC $0d $0a” on serial port, returns nothing.
  5. I have not changed the serial “data packing options”, all are default to 0.

Also, there is no response on sending VR and LI commands either.

Do you over see any problem?

I am really stuck into this from past several days.

Harish KS


please help.

Harish KS

Hi @Harish_Kumar_Singh,
Sorry for the late reply.

I checked the problem.
When using the WIZ750SR-RS485 module, can enter ATMODE and change settings, but cannot receive the response.

Can you connect the debug port? Operation information can be checked through the port.

After confirming this issue with the engineer in charge, we will let you know.

As you said, it seems to be a bug that only occurs when using wiz750sr-485.

Please download the firmware and upload it through the WIZconfig tool to test it.

WIZ750SRv133_#24_issue.zip (27.9 KB)

You can see the return message through the RS485