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The timestamp is similar to the one in Pseudobinary C. Pseudobinary D is smaller than
Pseudobinary C and it lacks detailed timestamps that would allow one to completely reconstruct
the time the data was collected from the message itself. To correctly use Pseudobinary D, the
decoder needs to know the measurement setup used.
The benefit of using Pseudobinary D is being able to correctly decode data regardless of when it
was sent or received. This allows stations to re-transmit old data and have it correctly interpreted
by the decoder while keeping the message size at a minimum.
Name
Bytes
Description
Block ID
1
BLOCK-IDENTIFIER is always sent as "D" to
indicate that this is the pseudobinary D format.
Group ID
1
GROUP-ID can be "1" to indicate a scheduled
transmission, “2” meaning an alarm transmission,
and “3” indicating a forced transmission, or “4”
indicating a retransmission
Day
2
This 2 byte encoded 6 bit binary encoded number
represents the Julian day of the year. The day tells
when the transmission was originally scheduled to
take place
Time
2
This 2 byte encoded 6 bit binary encoded number is
a number of minutes into the day. It tells when the
transmission was originally scheduled to take place
Measurement
Data
3 for each
sensor
reading
Sensor data encoded 6 bit binary. The value
transmitted will be value * 10^RightDigits. The
string /// will be sent if the data was never measured
or had bad quality
Battery
voltage
1
This is the battery voltage measured prior to
making the transmission. The range of the number
will be -32 to +31 and can be converted to volts by
multiplying by 0.234 and adding 10.6 allowing a
range of 3.1 to 18.1 volts.
Six-Bit Binary Encoded Format
The six bit binary format is used to encode numbers into displayable ASCII characters. Notice
that fractional numbers cannot be represented, so for instance a battery voltage of 13.04 volts set
up with 2 right digits will be sent as 1304.
•
A 1 byte encoded number can range from -32 to +31.
•
A 2 byte encoded number can range from -2048 to +2047
