Sutron Corporation X-Link Operations & Maintenance Manual, Rev 1.63 5/24/2016 pg. 160
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 identifier
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, 3 indicating a forced
transmission, and 4 indicating a retransmission.
Day
2
This 2 byte encoded 6 bit binary encoded (see below)
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 (see below)
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
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.
All the required values for one sensor (most recent first)
before proceeding to the next measurement. This format is
similar to that used by the Sutron Satlink but different from
the 8210.
There will be 3 bytes of encoded data for every sensor
reading. The number of readings depends on the user
setup.
Additional
Measurements
Variable
If more than one measurement was set up for transmission,
more data will follow. Each measurement setup will have
data starting with the Measurement Delimiter and ending
with Measurement Data.
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.
16.5.1.
Example of Pseudobinary D
To help understand the message below, here is a relevant bit of X-Link's setup:
