17
Rev 1.5
3.4 Temperature Sensor Inputs
The CML has 6 temperature sensor inputs (semiconductor sensors with 1 kOhm resistance at
25°C)
In the event of an error, the status LED on the front panel will turned red.
The temperatures can be read with the SNMP network command
(crate.sens
or.sensorTemperature OID) or in SYScontrol window “Global”
Each temperature is compared with three threshold values.
(crate.sensor.sensorWarningThreshold, crate.sensor.sensorAlarmThreshold and
crate.sensor.sensorFailureThreshold OIDs).
The temperature threshold values can be read or write in SYScontrol
window “Temperature
Sensors”.
Figure 3-7:
Window “Temperature Sensors” in SYScontrol
Please set all group- thresholds to equal values.
Two different modes can be set. Please read more about the hysteresis control mode and the
linear control mode in the following paragraph.
To operate the device in the hysteresis control mode, it is necessary to swap the alarm with
the warning temperature value. The alarm temperature has to be less than the warning
temperature. The fan speed executes a hysteresis between the two temperature points of any
connected sensor between maximum speed and the nominal and minimal speed respectively.
If the
“sensorFailureThreshold” of any connected sensor is reached, the main power supply of
the system is switched off.
The controlling result of fan speed is pictured in figure 3.8.