Thermal Sensor; Figure 4-2: Thermal Sensor Location - Advantech IPC-623 Series User Manual

4.4 Thermal Sensor

There are two thermal sensors located at the rear plate of the
chassis. They attached to the upper left and upper right
corners of the chassis back plate. Please refer to Figure 4-2.
thermal sensor

Figure 4-2: Thermal sensor location

When inside temperature of the chassis is overheated, the
thermal sensors send a signal to the alarm board and a
continuous alarm will sound. To stop the alarm beep, press
the Alarm Reset button on the front panel. Please refer to
Figure 4-3 for the thermal sensor module layout. And users
can refer to the following temperature setting by adjusting the
switch.