HL6525rd: Secure tcp socket fails with particular data



I have a HL6528RD on a custom board, we are in the final stages of testing before release so it is quite important that I find a solution to this problem.

I have attached two files to this post, both show a secure socket being opened and data being sent. “success_case.txt” shows the module responding okay to the stream of data. “failure_case.txt” shows the device not responding to a very similar stream of data. I have tried sending this particular stream of data to the HL6528RD many times and on multiple devices and every time the HL6528RD does not respond. The device has been on test for weeks and this particular stream is the only one I have found where this occurs.

Each time I wait 20 seconds for an OK response, one does not arrive.
I can see from the server side that the data is being sent, even when the module doesn’t respond.

this is the ATI string for the firmware version: RHL6528RD.

Thanks in advance for helping me out on this one. I can’t figure out what is going on.

failure_case.txt (2.1 KB)
success_case.txt (2.3 KB)


Hi huw,

In failure case of AT+KTCPSND=1,2036
It seems you or the host side add CR/LF at the end of “–EOF–Pattern–”. so no OK will be returned. Please make sure no CR/LF at the end of “–EOF–Pattern–”.