Vecow RCS-9430F-GTX1080 User Manual page 59

2.3.13 MPCIE1 : Mini PCIe, mSATA
3 1
6 4
Both mSATA and mini PCIe share the same form factor and similar electrical
pinout assignments on their connectors. There was no clear mechanism to
distinguish if an mSATA drive or a Mini PCIe device is plugged into the socket
until recently that SATA I/O issued an ECN change (ECN #045) to redefine pin-
43 on mSATA connector as "no connect" instead of "return current path" (or
GND).
When an mSATA drive is inserted, its pin-43 is "no connect", and the respective
pin on the socket is being pulled-up to logic 1. When a mini PCIe device is
inserted, its pin-43 forces the respective pin on the socket to ground, or logic 0.
The pin assignments of MPCIE1 are listed in the following table :
MPCIE1
mSATA
GETTING TO KNOW YOUR RCS-9000F GTX1080 51