7
Message format:
Size
Name
Meaning
1B
Message length
Bits 0:6 - Message length in bytes, excluding length
field and optional age field.
Bit 7: If 1, age field is included.
(2B)
Optional age field
Age, uint16 * 60 seconds
1B
Message type
Type, e.g. 11 = Flagged utility
XB
Message data
Data based on message type
Message types
Message types:
•
10 Formatted measurement data
•
11 Flagged utility
•
12 Debug
The device may send other message types but those should be ignored. Start of next record can be found
based on the length field at start of every message.
Type 10: Measurement data
Measurement data using bit-flags to describe which measurement fields are included. If the device failed
to measure a value, that field will be missing. The format additionally contains status information bitflags
field and related to measurements after the measurement data section.
After measurement data, has status bitflags field describing which status fields are included, similarly to
the measurement bitflags. Generally if the device failed to produce a measurement, it will have a status
code to help identify the issue.
Size
Name
Value/Meaning
2B
Measurement format
Always 1.
1B
Measurement flags
Tells which of the measurement fields are included.
E.g.
0011 1110 = all 6
001
0
111
0
= All except T & dP
2B
0
–
T
Conversion: int16 / 100 (
o
C)
2B
1
–
RH
uint16 / 100 (%)
2B
2
–
Reserved
Reserved for future use
2B
3
–
VOC
uint16 (ppb)
2B
4
–
dP
int16 / 100 (Pa)
2B
5
–
CO2
uint16 (ppm)
1B
Status flags
Tells which of the measurement status fields are
included.
1B
0
–
T status
0: Reserved for future use
1+: error number
1B
1
–
RH status
-||-
1B
2
–
absP status
-||-
1B
3
–
VOC status
-||-
1B
4
–
DP status
-||-
1B
5
–
CO2 status
-||-
