Hi,
The situation seems to be that sometimes packets sent to WIZ145SR (firmware 1.6.1) from ethernet will be written into the middle of the packets coming in from the serial port. Baud rate is 115200, WIZ145SR is configured as a tcp server and at the moment we’re sending data only through one serial port. Data rate is about 5kB/s, max 10kB/s. Overwrites occur maybe once per 2-10 minutes. We’ve observed the same behaviour with two (all we have at the moment) WIZ145SR modules.
For example, listening physically on the serial port rx line gives us this packet entering the wiznet module:
2014-03-31 16:49:25.85 85 bytes:
7ee3b283 03006c03 22484da7 311c6d1a aa4adfa3 75fce883 c6f0cec1 2de3d6b5 5c9fb9a3 e8b79aae ec7fb8b5 b2bafebb 363ecbe0 7f89d393 dd7c7d33 716f8fa3 3d68447c 7372a3ec ff000dbc 6cddbfd3 eded6cf6 7e
sudo tcpdump src 192.168.2.45 -x
gives us this same packet coming out of the wiznet module:
16:49:25.852130
7ee3b283 03006c03 22484da7 311c6d1a aa4adfa3 7edef685 e33c7e3c 2de3d6b5 5c9fb9a3 e8b79aae ec7fb8b5 b2bafebb 363ecbe0 7f89d393 dd7c7d33 716f8fa3 3d68447c 7372a3ec ff000dbc 6cddbfd3 eded6cf6 7e
The difference is “7edef685 e33c7e” in the middle of the tcp-dumped packet. This exact 7-byte packet is sent by our application once per second to the wiznet ethernet port in order to be forwarded to the serial port. But now it comes back out of the ethernet port while destroying some data.
Has anyone experienced something similar? I’d be happy to help debug the problem.
For reference, here’s the real tcpdump output of the packet under investigation with tcp/ip headers:
[code]sudo tcpdump src 192.168.2.45 -x
16:49:25.840483 IP 192.168.2.45.50001 > 192.168.2.61.56122: Flags [P.], seq 48808:48809, ack 1333, win 8190, length 1
0x0000: 4500 0029 0717 4000 8006 6dfd c0a8 022d
0x0010: c0a8 023d c351 db3a 74d2 323f a03a 5618
0x0020: 5018 1ffe 5021 0000 7e00 0000 0000
16:49:25.843147 IP 192.168.2.45.50001 > 192.168.2.61.56122: Flags [.], ack 1340, win 8180, length 0
0x0000: 4500 0028 0718 4000 8006 6dfd c0a8 022d
0x0010: c0a8 023d c351 db3a 74d2 3240 a03a 561f
0x0020: 5010 1ff4 ce2c 0000 0000 0000 0000
16:49:25.852130 IP 192.168.2.45.50001 > 192.168.2.61.56122: Flags [P.], seq 48809:48893, ack 1340, win 8190, length 84
0x0000: 4500 007c 0719 4000 8006 6da8 c0a8 022d
0x0010: c0a8 023d c351 db3a 74d2 3240 a03a 561f
0x0020: 5018 1ffe ebe3 0000 e3b2 8303 006c 0322
0x0030: 484d a731 1c6d 1aaa 4adf a37e def6 85e3
0x0040: 3c7e 3c2d e3d6 b55c 9fb9 a3e8 b79a aeec
0x0050: 7fb8 b5b2 bafe bb36 3ecb e07f 89d3 93dd
0x0060: 7c7d 3371 6f8f a33d 6844 7c73 72a3 ecff
0x0070: 000d bc6c ddbf d3ed ed6c f67e[/code]