Pathfinder DVL Guide
April
2018
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Page 173
BIT Decoding Method
In order to verify if the system has a BIT set for an ensemble, run the file through BBCheck.exe or decode
it from the
PD0
binary output using BBConv.exe.
BBCheck
and
BBConv
are
included with RDI Tools.
In any case, one will obtain a decimal value greater than zero if a BIT was set during the ensemble.
To decode it, simply convert the decimal value to Hexadecimal and take the first number to the far left as
being the number of BIT failure occurrences during the ensemble and the 2 other numbers on the far right
to be the BIT code.
For example:
•
BIT obtained from BBCheck or BBConv.exe is ‘290’.
•
Converted to hexadecimal (one can use the Windows calculator for this) gives: ‘122’.
•
Where ‘1’ is the number of occurrences for that BIT and ‘22’ is the BIT failure code which means
“Temperature Sensor failure” (see binary bytes 13 and 14).
Transducer Voltage, Current, and Impedance
The Transmit Voltage, Transmit Current, and Transducer Impedance values output in the
PD0
Variable
Leader are obtained from the Transducer Health Monitor measurement, which is part of the
. The measurement is made at the following times:
•
During the transmit pulse of a BM8 ping, if the expected altitude >= 20 m
•
During the transmit pulse of a BM9 ping, if the expected altitude >= 20 m
The transmit signal needs to be at least a certain length in order to make a valid
measurement.
The measurement is not made during any profile ping or water mass layer ping. Therefore, if bottom
pings are not enabled (or not working), then the output of these parameters will be 0xFFFF (i.e. hex
FFFF) to mark them as invalid (Note that hex FFFF is equal to decimal 65535 if interpreted as an un-
signed number, or -1 if interpreted as a signed number).
If bottom pings are enabled, but the altitude never attains 20 m or above, then the outputs for these pa-
rameters will remain at their initial values of 0xFFFF.
If a bottom track ping ever sees an altitude >= 20 m then these parameters will be measured and output.
If the altitude then goes below 20 m, the output of these parameters will remain at their last measured
value; i.e. you need a bottom track ping with altitude >= 20 m to update these values.