Table 5-11: User and system alarms break down
Alarm
Range
System status
Definition
Internal voltages
0 or 1
3
0 = No errors
1 = One or more errors reading user
variables from flash occurred
Spare
–
–
Reserved for future use
1
With OS version 9 or newer, this alarm flag will not increase in level until the dirt detector has been above the "dirt"
threshold continuously for 15 minutes or more. This prevents transient setting of the flag caused by reflections,
insects, or dust.
2
With OS version 9 or newer, this alarm flag will not change to level 1 unless the sensor has been continuously
saturated for 60 minutes or more. This is to avoid false alarms if the sun shines directly into the sensor.
6. Interface methods
6.1 Command line menu
The CS140 can be setup and controlled in one of two ways. The first method is by using the
command line interface where discrete commands are sent without response from the sensor.
This method is preferred for setting up a CS140 that is connected to a data logger. The data
logger can send configuration setting commands to the CS140 removing the need for a
computer to set up the unit.
The second method is by using the simple menu interface built into the CS140 using RS-232 or
RS-485 communications and a terminal emulator program. This menu system gives access to the
more common settings.
CS140 Background Luminance Sensor
14
