Asus P5KPL/EPU - Manual (Page 33)

ASUS P5KPL/EPU 1-23
3. Serial ATA connectors (7-pin SATA1-4)
These connectors are for the Serial ATA signal cables for Serial ATA hard disk drives.
4. Chassis intrusion connector (4-1 pin CHASSIS)
This connector is for a chassis-mounted intrusion detection sensor or switch. Connect
one end of the chassis intrusion sensor or switch cable to this connector. The chassis
intrusion sensor or switch sends a high-level signal to this connector when a chassis
component is removed or replaced. The signal is then generated as a chassis intrusion
event.
By default, the pin labeled “Chassis Signal” and “Ground” are shorted with a jumper
cap. Remove the jumper caps only when you intend to use the chassis intrusion
detection feature.