Message structure

Basic format
STX	Message ID	Sensor ID	System Status	Luminance	Units	Checksum (CCITT)	ETX	Carriage return	Line feed
0x02	0	0	3	35833.7	1	4E7C	0x03	0x0D	0x0A

 

Partial Format
STX	Message ID	Sensor ID	System Status	Message Interval	Luminance	Units	User alarms	Checksum (CCITT)	ETX	Carriage return	Line feed
0x02	1		3	10	15732.2	1	0 0 0 0	1ED9	0x03	0x0D	0x0A

 

Full Format
STX	Message ID	Sensor ID	System Status	Message Interval	Luminance	Units	Average duration	User alarms	System alarms	Checksum (CCITT)	ETX	Carriage return	Line feed
0x02	2	0	3	10	15292.4	1	1	0 0 0 0	1 0 0 0 3 0 0 0 0 0 0 0	F8DA	0x03	0x0D	0x0A

 

Message ID break down
ID	Definition
0	Basic format. Contains only luminance and system information
1	Partial format. Contains user alarm outputs
2	Full format. Contains all system alarms codes

 

Sensor ID break down
ID	Definition
0 to 9	Unit number defined by the user to aid identification of data. Default is 0. Useful for RS-485 networks. Operates as an address in RS-485 mode.

 

System status break down1,2
Status level	Definition
0	Basic format. Contains only luminance and system information
1	Partial format. Contains user alarm outputs
2	Full format. Contains all system alarms codes
1System status break down reflects the highest level of severity of any active alarm. 2Refer to the individual alarms (below) for details of the response times of the alarms.

 

Message interval
Time	Definition
1 to 3600	The amount of time, in seconds, between outputs in continuous mode

 

Luminance break down
Luminance	Definition
1 to 50000	Current luminance being detected by the sensor. The maximum luminance level reported by the sensor can be defined by the user via the menu system.

 

Visibility units break down
Option	Definition
1	cd/m2
2	fL

 

Averaging duration break down
Duration	Definition
1	One minute average
10	Ten minute average

 

User and system alarms break down
Alarm	Range	System status	Definition
User Alarm	0 or 1	1	0 = User alarm not active. 1 = User alarm active.
Spare	0	–	Reserved for future use.
Spare	0	–	Reserved for future use.
Spare	0	–	Reserved for future use.
Window contaminated1	0 to 3	0 1 3	0 = OK. The reported attenuation is below 10%. 1 or 2 = Reported dirt level is over 10%. 3 = High level of returned dirty signal. This could be either a blocked sensor or a broken dirty window system.
Photo diode temperature	0 to 3	0 1 1 3	0 = Temperature is within operating conditions. 1 = Too low. Less than –40 °C. 2 = Too high. Over 70 °C. 3 = Sensor fault (No sensor detected or below –49°C).
Hood temperature	0 to 3	0 1 1 2	0 = Temperature is within operating conditions. 1 = Too low. Less than –40 °C. 2 = Too high. Over 70 °C. 3 = Sensor fault (No sensor detected or below -49°C)
Detector DC saturation level2	0 or 1	0 2	The amount of background light as seen by the detector hood. 0 = Within limits. 1 = Saturated. The CS140 is experiencing direct light levels that are saturating the photo diode.
Signature error	0 or 1	3	0 = Signature of entire flash was checked and matches the stored version. 1 = Signature does not match previous readings.
Flash write error	0 or 1	3	0 = No errors. 1 = One or more errors reading user variables from flash occurred.
Internal voltages	0 or 1	3	0 = No errors. 1 = One or more errors reading user variables from flash occurred.
Spare	0	–	Reserved for future use.
1 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 alarm flag will not change to level 1 unless the sensor has been continuously saturated for 60 minutes or more. This prevents false alarms if the sun shines directly into the sensor.