Sutron Corporation Satlink Operations & Maintenance Manual, Rev 8.04.2 11/3/2016 pg. 134
15.
Transmission Data Formats
15.1.
Pseudobinary B Data Format
This format is based on GOES Pseudobinary format. It is used when the user selects P
seudobinary
B
as the choice for
Tx Format.
The format uses ASCII characters. Three bytes are used for each
data value. To correctly decode the measurement, you need to know how many readings of each
measurement are included in the transmission. There is no metadata that would describe which
measurement is which.
15.1.1.
Pseudobinary B for Random Txs
Random transmissions are always made using Pseudobinary B. Their formatting is unique. These
are the fields that appear in Pseudobinary B Random transmissions:
Field
Pseudobinary B for Scheduled and Alarm Txs
GROUP ID
GROUP-ID is sent as 2 to indicate a random transmission. Compare this to
scheduled transmissions which have a B1 as their ID.
OFFSET
Each record is prefixed with an <OFFSET>, which is a 1 byte binary encoded
number indicating the number of minutes ago the most recent data was
recorded. .
MEASUREMENT
DATA
Measurement data collected: This data contains only those measurements set
up to be included in the transmission (see
Tx Data Content)
. The data values
are 3 byte binary encoded signed numbers allowing a range of: -131072 to
+131071. The actual 6-bit binary encoded format is described later. The value
transmitted will be value * 10^RightDigits. The string /// will be sent if the
data was never measured or was erased.
The number of values sent for each measurement is set separately for each
measurement in the Scheduled Transmissions, Num values to Tx field. Note
that this is different from the 8210 where the num values to Tx was the same
for each sensor. As a result, Satlink Logger sends all the required values for
one sensor (most recent first) before proceeding to the next measurement. In
the 8210, values were interleaved.
EXTERNAL DATA
[OPTIONAL]
This is data given to Satlink Logger by an external device. This data is
untouched by Satlink Logger. It gets transmitted in the same way it was
received.
Data will only appear here if another logger gives Satlink transmission data. It
is not usual to have both Measurement Data and External Data.
LAT/LONG
[OPTIONAL]
This 8 byte value is appended only if the correct Append Option is selected.
LAT/LONG can be decoded into D:M:S format by converting the binary values
to decimal and applying the following formula:
Degrees latitude = 64 * ( 1st-byte AND 63 ) + ( 2nd-Byte AND 63) − 90
Minutes latitude = 3rd-byte AND 63
Seconds latitude = 4th-byte AND 63
Degrees longitude = 64 * ( 5th -byte AND 63) + ( 6th -Byte AND 63) − 180
