On Sun, 28 Aug 2016 09:59:44 -0700 (PDT), wrote:

Here is another quote:

"Just a note to add that if you use the version of those Sunon fans
with the "F" 3rd wire output (frequency or "tacho" output) then the
switch will register a fan fail - you need the version that has the
"R" (Rotation) type 3rd wire output which is a basic constant 5v
or 0v output depending on whether the fan is stalled or running"

https://www.youtube.com/watch?v=1_dM0pBRfOI&t=0s

Well, that's your answer on the part number.

However, you can probably simulate the "R" type by simply integrating
the frequency output of the "F" type with a large capacitor. To the
Dell switch, the pulse train would look like a DC voltage. It's easy
enough but I don't want to recommend a circuit until I see what kind
of load the Dell represents (TTL, CMOS, transistor circuit, etc) and
what levels it expects.

F versus R type:
http://www.sunon.com/uFiles/file/03_products/07-Technology/005.pdf

You could also just pull down to ground the 3 fan sense wires on the
Dell. (see waveform on the R type above). There would not be any
indication of a fan failure, but it would work.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558