WIZnet Developer Forum

Sending fake packets at wiz750sr-rs485

We have a situation where the PC sends a UDP packet to the WizNET device, it passes it to the RS485 line and immediately after exposing all data to the line
sends our device data that WizNET has to buffer and send UDP packet. This happens, but before sending Wiznet data to UDP, it has time to send another packet with fictional data.
It doesn’t always happen, according to observations, especially for larger packets, but even that causes us problems, because not all our programs can rule it out.

I am sending a record of communication directly on the RS8485 line with comments (captured by RealTerm, in the next screen attachment)
Direct log from RS485 bus:(sends WizNET to the line)
01 FB 00 FF 00 00 19 33 61 00 00 00 A3 C0 07 07 A5 C0 07 07 80 C0 07 07 A1 C0 07 07 9B C0 07 07 9D C0 07 07 0B 93 DF 63 0B 93 A4 2F 0B 93 F4 60 95 C0 07 07 9F C0 07 07 91 C0 07 07 8B C0 07 07 8D C0 07 07 97 C0 07 07 89 C0 07 07 C3 80 47 47 C5 80 47 47 CF 80 47 47 C1 80 47 47 3B 80 47 47 3D 80 47 47 C7 80 47 47 39 80 47 47 4B D3 3D 1F 4B D3 E6 1F 3F 80 47 47 4B D3 14 1F 2B 80 47 47 2D 80 47 47 37 80 47 47 29 80 47 47 E3 40 87 87 E5 40 87 87 8B 13 07 E4 E1 40 87 87 DB 40 87 87 DD 40 87 87 E7 40 87 87 D9 40 87 87 D3 40 87 87 D5 40 87 87 DF 40 87 87 D1 40 87 87 CB 40 87 87 CD 40 87 87 D7 40 87 87 C9 40 87 87 83 00 C7 C7 85 00 C7 C7 8F 00 C7 C7 81 00 C7 C7 FB 00 C7 C7 FD 00 C7 C7 87 00 C7 C7 F9 00 C7 C7 F3 00 C7 C7 F5 00 C7 C7 FF 00 C7 C7 F1 00 C7 C7 DF 8A 02

(sends our device to the line)
01 0B 00 00 00 FF 19 33 E1 00 00 00 B3 B4 02
UDP data with comments (captured by Packet Sender)
(PC sends to WizNET : )
01 FB 00 FF 00 00 19 33 61 00 00 00 A3 C0 07 07 A5 C0 07 07 80 C0 07 07 A1 C0 07 07 9B C0 07 07 9D C0 07 07 0B 93 DF 63 0B 93 A4 2F 0B 93 F4 60 95 C0 07 07 9F C0 07 07 91 C0 07 07 8B C0 07 07 8D C0 07 07 97 C0 07 07 89 C0 07 07 C3 80 47 47 C5 80 47 47 CF 80 47 47 C1 80 47 47 3B 80 47 47 3D 80 47 47 C7 80 47 47 39 80 47 47 4B D3 3D 1F 4B D3 E6 1F 3F 80 47 47 4B D3 14 1F 2B 80 47 47 2D 80 47 47 37 80 47 47 29 80 47 47 E3 40 87 87 E5 40 87 87 8B 13 07 E4 E1 40 87 87 DB 40 87 87 DD 40 87 87 E7 40 87 87 D9 40 87 87 D3 40 87 87 D5 40 87 87 DF 40 87 87 D1 40 87 87 CB 40 87 87 CD 40 87 87 D7 40 87 87 C9 40 87 87 83 00 C7 C7 85 00 C7 C7 8F 00 C7 C7 81 00 C7 C7 FB 00 C7 C7 FD 00 C7 C7 87 00 C7 C7 F9 00 C7 C7 F3 00 C7 C7 F5 00 C7 C7 FF 00 C7 C7 F1 00 C7 C7 DF 8A 02

(Receiving a fictional packet to a PC from WizNET)
1D 87 D9 40 87 87 D3 00
(Receiving the correct packet to the PC from WizNET)
01 0B 00 00 00 FF 19 33 E1 00 00 00 B3 B4 02

I want you to first check the packet via wireshark.
Please capture the packet and attach it.
https://www.wireshark.org/download.html

Hello,
I send. Fake packets are in times:
1.972713
2.153772
2.341711 etc.
Data that is physically on the line always starts at 0x01 and ends at 0x02ELVIS.zip (11.2 kB)

Good day.
We have sent you the required data and I ask for your opinion or what else you need from us.
Thank you

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