CMi6110
User’s Manual English
CMi6110 User’s Manual English
page | 29 (42)
[2022-10]
v1.3
Base Time
•
Base time
is used to set a reference time.
o
Timestamps are always encoded according to SenML (i.e., UNIX time). SenML label -1
“Base time”, SenML definition of Time field
o
This value MUST be included in the first record of the pack
o
All other values have a
time
value that is added to the
base time
to define the exact time
of the readout
Base Name
•
Base name
is used to represent the MeterID (Meter identification in M-Bus)
o
This value MUST be included in the first record of the pack
o
This is represented as a string array (CBOR Major Type 3 - SenML label -
2 “Base
name”)
▪
The product shall specify the exact format for this field, as it may vary depending
on what type of “meter” is used. For an M-Bus format it is typically the M-Bus
data without DIF/VIF.
o
No
name
is set for remaining meter readout values, only values belonging to a single
meter can be represented in one pack.
Data values
•
The actual values from the meter can be encoded using multiple methods, such as M-Bus.
•
The first record can also contain a data value field containing more information than the
remaining records in the pack. This is to include more information for the first reading and then
only a subset of values for the remaining records to save space. (SenML label 8 -
“Data value”)
Other values
•
(Base) Unit
is not used, since the unit is specified by the M-Bus data
•
An “Encoder Version field” is used in a separate record to define the type and version of the
encoded payload data.
Additional Records
All records in the SenML pack are expected to contain measurement values. If there is a need for
transmitting additional information in the same pack additional records can be added. For such records
the name field shall be used by defining a name of at least a single character. In SenML the
base name
and the
name
fields are appended to result in the final record name.
The
name
shall contain at least one character outside [A-Fa-f0-9] which signifies non-hexadecimal
representation, since meter-id is typically decimal/hexadecimal, and this makes it easier to check the
record name for validity.
If a parser finds a record with a
name
field like described above that it does not recognize it shall ignore
the record.
The following additional records are currently used
Record
Name field
Comment
Encoder Type &
Version
”V”
This field allows defining versions for the
contents of the measurement field.