WINC1500 missing transmission
In my project, I'm running into an issue with the WINC1500 driver/chip.
This project is based on the example TCP server bundled with harmony. The only modification is that it is performing modbus operations and sending back the result. This is usually running fine, but in one specific case, the transmission is not as expected.
This is when I'm using an external system (ARM-based sigmatek PLC) to perform modbus operations. In this, the first TCP message is missed and as a result, no reply is sent. This is a continuous problem when using the default timeout at the PLC (2 seconds). However, when I reduce this timeout to 100 ms, the first message is still missed, but the second (100 ms later) is received fine and a response is also seen.
When I place a breakpoint at the socket callback function, the first message I receive is an 0xFFF4 in the bufferlength, which is the socket abort. In other words, the first message never reaches the callback.
The WINC1500 has firmware v19.6.1 and the driver is using version 19.3.0.
Any ideas on what could be causing this?
I've attached three wireshark captures that show the problem, just rename .txt to .pcapng
If more information is needed or if this raises more questions, please let me know.
Forgot to add, this is on a custom board using a PIC32MX795F512L, the WINC1500 is connected on SPI2.
post edited by riwo_rens - 2020/06/16 03:12:47