4-14
8011M ACOUSTIC DECK UNIT
0004811_REV_F
4.2.2
Ranging (<RNG>)
Ranging parameters can be set on the 8011M. They are: Interrogate Frequencies, Reply Frequencies, Turn
Around Time (TAT), Upper Range Gate, Lower Range Gate, and More Options.
1.
Press <
MENU
> and select
Range Setup
and select
Interrogate Frequencies
and
Reply Frequencies
to set the proper interrogate and reply frequencies. The interrogate frequency is the frequency
transmitted from the 8011M deck unit, and the reply frequency is the frequency received by the
8011M deck unit.
a.
For correct frequencies, refer to the configuration sheet supplied with the Unit.
NOTE:
If testing an underwater unit in the air, use item 5 to change the
minimum range gate to “0”. This will allow the deck unit to receive the
replies in the air even though the reported ranges will not be accurate.
2.
Press <
MENU
> and select
Range Setup,
and select
TAT
. This is the internal delay time in the
underwater unit from when it receives the interrogate pulse until it responds.
•
The default is 13 milliseconds. This is the correct value for use with EdgeTech and ORE
Offshore equipment.
•
When using other manufacturer’s equipment, change this value.
•
The value is entered in milliseconds, and the range is 0 to 2000 milliseconds.
•
When calculating ranges, this time is subtracted from the total two-way travel time of the
acoustic path.
3.
Press <
MENU
> and select
Range Setup
and select
Upper Range Gate
and
Lower Range Gate
. Any
replies received before the lower range gate or after the upper the upper range gate are ignored.
These gates can help alleviate random noise being treated as a valid reply.
•
The default lower range gate is 50 meters an underwater unit closer than 50 meters will
be ignored by the deck unit.
•
The upper range gate is 16383 meters. Any underwater units further away than 16383
meters will be ignored.
