• Description of use case
We have an AP with a web server, the ECU are called AU.
For fault tracing, we have a minimal app, for each iteration:
1. Connects to server
2. From TC20 and TC21 we are fetching one json file (192.168.242.1:3001/.../planogram)
3. Closing connection
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* AU *
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AU has a imx6 and TI chip - WL1837MOD.
It has a Yocto project - linux-variscite
chip.id = 0x6030111
chip.fw_ver_str = Rev 8.9.0.0.85
chip.phy_fw_ver_str = Rev 8.2.0.0.245
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* Zebra TC20/TC21 *
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TC20 and TC21 are zebra devices. Mobile phones/scanners
TC20 - 8.1.0
TC21 - 10
•What is the problem description?
With TC20 we always get stuck after a while, i.e. communication between TC20 and AU are not working. Re-transmissions and ARP messages that are not handled.
If we ping TC20 from AU, we got less errors, and communication are coming back if we get faults.
With TC21 it is working fine. I have only got one re-transmission that couldn't be sorted out. Communication continued after that fault.
•Figures describing issue
* TC20 logs
1_From_TC20_log__AU_doesnt_replay.png
First part shows correct behaviour. Connects to AU, request data (get handheld/planogram), disconnect
New run, AU doesn't respond.
ARP request are send out since no response.
2_From_TC20_log__AU_finaly_responds_on_arp_zebra_makes_rst.png
We got ARP respone from AU
Zebra sends out frames and make a reset.
After this it works as intended.
* AU logs
3_From_AU_log__Correct_message_no_messages_from_TC20.png
First part shows correct behaviour. Connects to AU, request data (get handheld/planogram), disconnect
New run, zebra frames doesn't come.
No ARP request seen from TC20 (zebra)
4_From_AU_log__zebra_gets_arp_response_from_AU_RST_and_it_works_again.png
ARP request from zebra
AU responds (blue marked)
Communication starta. Zebra resets and it works as intended again.
* Monitor mode
5_OTHER_log_occation_monitor_mode_AU_doesnt_respond
I have also seen this in monitor mode logs (monitor wifi network), but I don't have this for this run.
Adding figure from previous testing.
•Questions
- I don't know if it is related, but the error seems to come back around every 20 minutes.....
- How do I disable ARP filtering on WL1837MOD? Could test if it is working better if filtering are disabled.
- Any other ideas why we don't see zebras messages (both SYN and ARP) in AU?
