Sending fake packets at wiz750sr-rs485

S2E Module WIZ750 Series
1

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

2

WizNET_UDP
WizNET_UDP911×778 41.5 KB

3

WizNET_RS485
WizNET_RS485879×820 45.1 KB

4

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

5

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)

6

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

7

I tested by configuring an environment similar to yours as much as possible. But I didn’t get a fictional packet like you. Please check the options and whether other data is transmitted by the serial tool. Additionally, if your stop byte is 0x02, it is recommended to give packing conditions like mine.

image
image911×755 47.5 KB

image
image775×679 7.37 KB

WIZnet_ELVIS_Test.zip (467 Bytes)

8

Good day.
this is how we set up wiznet with us.

WizNET
WizNET902×747 45.5 KB

9

Hi Wiznet team, R&D team from ELVIS contacted us again, and it’s still not working properly.
Device is still sending ‘‘fake’’ logs, even when they’ve used your recommended setting.
Regarding their feedack, it’s not same with every log sent, however it looks there is same patern in it for simmilar logs as they’ve already sent (posted earlier in chat).
Would you mind help us more or willing contact customer directly and try to find any solution how to fix it?
Otherwise they will have to change Wiznet devices for other producer.