Oh, I forgot to mention...
The board is Duet2 Ethernetv1.04, running RRF3.2.2 and DWC3.2.2.
The fan is of course powered by an external 5v supply.

Hey there.
I'm using this 5vfan for my hot end fans
I noticed that the fan was reading strangely high, so I checked the datasheet one more time and discovered that it was spec'd for 4 pulses/rotation.
I remember that normal fans are 2 pulses/rotation, so it makes sense that a 7000 rpm fan is always showing more than 13000 rpm on the DWC.

Here are the settings for this fan in config.g
M950 F1 C "fan1+^exp.pb6" Q500
M106 P1 C "ColdEndFan" S1 H1 T45

The connection is to PB6 via 1N4148 as @dc42 has explained many times in previous threads.

Is there any way to change the pulse per revolution setting?

I expect so much.

@Danal
Sorry for the confusion on the Japanese page, thanks for looking seriously.
May be this picture is a good explanation of what this device can do.

@dc42 So that's it.
Thanks for the great effort, may be try to make a breakout board someday.
I feel sad that WROOM module was not chosen, no help for a larger footprint.
The big reason I want to replace a Wifi module is mDNS protocol.
Are there any plans to implement the mDNS protocol on the Duet2Ethernet?

Yeah I know, such like WRH-583BK2-S
or as you said RPi can bridge between the wifi client and the ethernet port, right?
I just wondering what kind of network device can just being the client Instead of connected ethernet ,not bridge or AP.

@Danal
before posting here I was thinking about plug a Wifi Bridge.
A device acting as a client may different from a bridge or AP,I have never seen such a thing
For example, what kind products can be used?

@bearer
Wow Duet 3? You say remove the ethernet module and connect the Pi to duet board directly?

@bearer
The original ESP8266 wifiserver doesn't seem to work well with 2MB flash..
(https://github.com/dc42/DuetWiFiServer >> https://reprap.org/forum/read.php?2,582444,582444#msg-582444)
and ESP-07 has only 1MB flash, but ESP-07S seems to have 4MB
ESP-WROOM-02 with 2MB flash may not be good idea
At least,it looks physically possible without magical smoke or some thing, thanks to the powerful onboard flash of the reprap firmware.
thanks for infomation.

@bearer
I'm prepared to change the wiring or make some sort of breakout board, but whether need to edit the firmware or do some program thing?
The module used must be certified by TELEC (MIC). As far as I know the only EXP8266 module that has passed this certification in Japan is ESP-WROOM-02. (https://www.espressif.com/sites/default/files/esp-wroom-02_telec_certificate.pdf)
The manufacturer of ESP-WROOM-02 is Espressif Inc, and the ESP-13 seems to be AI-thinker. There seems to be no difference in function, footprint, and pin assignment.