Klein 3900 Series Operation And Maintenance Manual page 79

B-5
Startup Script
LBOGAIN {d = 0 – 3}. Along with the PREEMPHAIS variable (see above)
this allows longer cables to be driven. The default value of '1' provides for
optimum performance on short to medium length cables. A value of '0'
decreases the uplink signal level by 6 dB. This is useful when operating the
sonar on an extremely short cable such as when testing using only the deck
cable as the level in to the TPU would normally be too high and may cause
telemetry errors. For longer cables setting the value to '2' increases the level
by 6 dB, a value of '3' increases the level by another 6 dB. Using the $MGx
fish command along with the $MLx fish command the optimum combination
of gain and pre-emphasis can be found. These values can then be applied on
turn-on by entering the appropriate values into the startup script. NOTE: This
is only supported on towfish equipped with the 14102066 Multiplexer PCB.
GETRAWDATA {d = 0,1}. Setting this to '1' instructs the TPU that the raw
data acquisition modification has been performed. This modification allows
the TPU to acquire and save raw stave data. Contact the factory for more
details.
INCLUDE_IPMC761 {d = 0,1}. If the TPU host CPU is an MVME51xx
series CPU board and has been outfitted with an IPMC761 PCI Mezzanine
Card this should be set to '1'. This instructs the TPU to use the features of the
IPMC761. The IPMC761 is factory installed when the system is modified for
raw data acquisition.
DEFAULTUPLINK {d = 0,1} (3000 System only). The default operation of
the 3000 System telemetry subsystem utilizes a party-line topology where the
various serial data sources are routed to the uplink auxiliary serial channel
depending upon the downlink message destination (the main uplink serial
channel is dedicated to sensor data packets). For example, if the downlink
message were a compass command the uplink serial channel would be routed
to the TX output of the compass and all compass output data would appear at
the TPU auxiliary serial port (COM3). However, this can be over-ridden by
setting DEFAULTUPLINK to '1'. This tells the towfish to reset the uplink
auxiliary serial channel to the towfish auxiliary RS-232 input after each
downlink message. This is useful when, for example, a magnetometer or other
free-running sensor is connected to the towfish auxiliary RS-232 input. This
allows that sensor data to be constantly output from the TPU auxiliary serial
port regardless of any downlink commands. Default is '0'.
BEAMBALANCE {d = 0 – 1000} (5000 System only). Version 5.3 and
later of the TPU software has an improved beam balancing algorithm. The time
constant of the balancing filter is variable and is set with this command. Lower
values allow the filter to compensate for beam imbalance faster but may reduce
data quality somewhat as the filter may respond to geographic features. Higher
values slow the adaptation rate but may not allow the filter to adapt to