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07/2020
Corona II
– LED Line Scan Illumination
PMA_CHR_CD40069_R05_Manual_Corona-II_XLC4
142
8.1.3 Fan monitoring
Chromasens has introduced the option for fan monitoring step by step for new Corona
modules starting with shipments in 2016. Please contact Chromasens for more details about
the supported Corona models.
In the XLC4 controller, the fan monitoring is supported by firmware release 5.1 or higher.
General function:
Fan monitoring is working with a voltage measurement at the input ACTRL at the connector
X5 pin 1.
The fans of supported Corona modules are equipped with an open-drain-switching-output.
This output is switched to ON if the fan is working. In the modules the outputs are connected
with a serial resistor of 1100Ω to a common signal. This signal is connected to ACTRL. In the
XLC4 controller (starting with hardware release ES2) there is a pull-
up resistor of 820Ω
between the input ACTRL and VOUT.
If the fans (up to 4) are switched with VOUT and all fans are working, all the switching signals
are set to Low signal. Depending on the number of the connected fans and the level of VOUT
there will be a specific voltage at ACTRL. This voltage is measured by the XLC4 controller.
For correct interpretation of the signal, the XLC4 controller needs knowledge about the
connected number of fans. This value is stored in the I²C chip on the Corona and is read at the
start-up of the controller. With these values the controller is calculating a specific alarm level
for the signal from the fans.
•
Number of fans for the specific Corona
•
Value for the pull-up resistor (always 0 because it is integrated to the XLC4)
•
Value for the serial resistor in the Corona (always 1100 for Corona models)
To start the fan monitoring, the bi
ts 3 and 4 in the register „FA“ have to be set to „1“:
Sample:
S: FA 0x18 R:fa 0x0018