Asus MAXIMUSII/FORMULA - Maximus II Formula Motherboard User Manual page 55

8. Thermal sensor cable connectors (2-pin OPT_TEMP1/2/3)
These connectors are for temperature monitoring. Connect the thermal
sensor cables to these connectors and place the other ends to the devices
which you want to monitor temperature. The optional fan1/2/3 can work with
the temperature sensors for a better cooling effect.
Enable OPT FAN1/2/3 overheat protection in BIOS if you connect thermal
sensor cables to these connectors. Refer to page 3-36 for details.
The thermal sensor cable is purchased separately.
9. 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.
ASUS Maximus II Formula 2-29