Connection error 0x848a0007 (Response from the server was bad)

[AELhammoudi]

I am using a customized board based on IMXRT1175CVM8A. The manufacturer is using an application that runs on two cores, one acting as the master and the other as the slave. It uses an executable to act as the server, splitting multiple channels (master, slave), and has a settings file to set the ports and the CAN Tx and Rx IDs to be accessed via the HTTP plugin.

The configuration for communication is as follows:
```
// Select communication interface
#define FMSTR_TRANSPORT FMSTR_SERIAL // Use serial transport layer
#define FMSTR_SERIAL_DRV FMSTR_SERIAL_BSP_COM // Use serial driver for UART

```

I need to run Telnet like Tera Term on the specified port. Although it connected to the port when trying to connect, but it raised an error "bad response from the server." I have searched on the forum for a similar issue but couldn't find any solution.

any ideas how to resolve this issue please?

[AELhammoudi]

Hello,

thank you for your response!

they are using a customized remote server which depends on a cr extension file which has the settings of the communication :


"Freemasters": [
{
"Name": "Freemaster Master M4",
"Port": 8080,
"Enabled": true,
"CANInterface": {
"RxChannels": [
{
"CanId": "0x511"
}
],
"TxChannels": [
{
"CanId": "0x502"
}
]
}
},
{
"Name": "Freemaster Slave M7",
"Port": 8090,
"Enabled": true,
"CANInterface": {
"RxChannels": [
{
"CanId": "0x510"
}
],
"TxChannels": [
{
"CanId": "0x501"
}
]
}
}
],

I have attached the Wireshark capture the connection requests, I have tried to run the customized serve first and then the Ter term on the port 8080 and capture the server response when trying to connect and getting same error

[MichalH]

Hello,

the error 0x848a0007 may be returned by FreeMASTER communication plug-in for accessing FreeMASTER Remote Server using HTTP protocol. The Remote Server then acts as a remote connection point for the target board. The Remote Server needs to have the HTTP port enabled and it should also understand the connection string passed to it by a FreeMASTER client. 

You do not mention use of the Remote Server application, nor its configuration. Also, your setting of FMSTR_SERIAL_DRV shows that you are using completely customized communication. If I understand it well, you try to use your manufacturer's implementation of HTTP protocol to access a custom version of the Remote Server. 

I'm afraid we cannot support you in this case, you shall contact the manufacturer who has developed the solution. 

If you post a Wireshark trace which captures the HTTP communication between FreeMASTER and the HTTP server, I could perhaps see where is the protocol violated causing the 0x848a0007 error.

Regards,
Michal