StarTech.com PEX8S950LP User Manual page 6

JP3, JP5 - External Power Enable/Disable Selector - JP3 is used to set pin #9 of DB9
connectors S1-S4 to either the RI (Ring Indicator Signals) or the 5V/12V DC Power
(selected by JP4). JP5 performs the same function for DB9 connectors S5-S8. When
the jumper is set to the "P" position, it will output the DC power over pin #9; if set to
the "D" position, pin #9 will be connected to the normal RI signal, based on the RS232
standard.
JP4 - Power Source Selector - Used to select DC power for pin #9 of the DB9
connectors. This can be set from PCI Express 12V or 12V (or 5V) from the 4-pin auxilliary
power connector.
Power source is set to
+12VDC from the PCI
Power source is set to
+5VDC from J3
auxilliary power
Power source is set to
+12VDC from J3
auxilliary power
Instruction Manual
Express slot
connector
connector
Default
Pin #9
connected
to power
3
Default