Waveshare Rs485 to POE ETH(B) - flash write error!
EDIT - Sorted itself out....not sure how.

I am definitely a beginner here.

I have a KH9.9 and have wired up a Waveshare Modbus adapter using POE.

I have the Modbus connected to a POE switch which is then connected to my Eero router.

When connected using POE, the power light on the WS is bright red. If I disconnect the ethernet cable and power the WS with a usb cable connected to a power socket, the power light is less bright.

With POE connected, I get a very faint yellow light on LINK. THe device is visible on Vircom.

My issue seems to be arising when I try to update the BIN file. I get a "flash wirte" error.

Any thoughts?

I've checked the wiring and pins and all seems fine.
Attachments:
Screenshot 2026-06-17 210323.png
USB cable powered
USB cable powered
POE power
POE power
Re: Waveshare Rs485 to POE ETH(B) - flash write error!
I don't have the PoE version myself but I know a lot of people that use it sucessfully.

The Waveshare has a wide voltage tolerance but when connected via USB it is at it's lowest range (it can be as low as 3.3V but more typically ~5V), whereas PoE is closer to 48V and so I would definitely leave it connected this way.

If it's showing in Vircom that is a good start, I know a few users have had to do factory resets when trying to flash firmware, from memory you have to add a link across a couple of pins to do that.

From my own experience of using the non PoE version, I found that the ethernet port isn't particularly fast (10-100Mb) and so I set it to a fixed speed rather than auto in the switch.
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