XLINK 500/100 Operations & Maintenance Manual page # 139
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 non-Random Txs
If the Pseudobinary B format is used for any transmission type except Random, it will have the
fields listed below. Scheduled and Alarm transmissions will use this format.
Field
Pseudobinary B for Scheduled and Alarm Txs
BLOCK IDENTIFIER
BLOCK-IDENTIFIER is always sent as B to indicate the start of a binary data
group.
GROUP ID
GROUP-ID is sent as 1 to indicate a scheduled transmission. Random and
alarm transmissions send 2. Forced send 3, while retransmissions send 4.
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, the station sends all the required values for one
sensor (most recent first) before proceeding to the next measurement. In the
8210, values were interleaved.
BATTERY VOLTAGE
[OPTIONAL]
This is an optional 1-byte binary encoded number representing the battery
voltage of the station.
This value is appended only if the correct Append Option is selected.
If the battery reading is zero, then that is the first transmission since bootup.
The range of the Pseudobinary number is -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.
STATION NAME
[OPTIONAL]
This is a variable length, space delimited field that contains the station name.
Space delimited means there is a space before and a space after the station
name. If the station name were set to SmallCreek, the transmission would
contain
