April
2018
Pathfinder DVL Guide
Page 104
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
#B2 - Depth Memory Timeout
Purpose
Enables Bottom Track to preserve the range-to-bottom across a Break. #B2 0 (default)
disables the feature. Setting #B2 to 1 to 30 sets a timeout, in seconds, after which the de-
vice will search for the bottom as normal.
Format
#B2 n
Range
n = 0, 1 to 30
Default
#B2 0
The default setting for this command is recommended for most applications.
Description
# B2 sets a time during which the DVL can retain the last known good range when a
Break is received followed by a CS command. This is especially useful as when sending a
Break the DVL will search for the bottom in its default configuration, setting the #B2 al-
lows to avoid searching for the bottom and thus benefits the user by offering a faster re-
start post break. In addition, this command has proven very useful to prevent the DVL
from locking onto interfering signals in noisy environments.
#BA - Evaluation Amplitude Minimum
Purpose
Sets the minimum value for valid bottom detection.
Format
#BAnnn
The BA commands work with or without the # sign. For example, using BA or #BA are both
valid commands.
Range
nnn = 1 to 255 counts
Default
#BA24
The default setting for this command is recommended for most applications.
Description
#BA sets the minimum amplitude of an internal bottom-track filter that determines bot-
tom detection. Reducing #BA increases the bottom-track detection range, but also may
increase the possibility of false bottom detections.
#BB – Bottom Blanking Interval
Purpose
This command sets the near limit of bottom detection beyond the transmit pulse.
Format
#BBnnnn
The BB commands work with or without the # sign. For example, using BB or #BB are both
valid commands.
Range
nnnn = 0 to 3200
Default
#BB0005
The default setting for this command is recommended for most applications.
Description
The Pathfinder will search for the bottom starting at the length of transmit plus this
blanking interval.