DVL Diagnostics

DVL problems include loss of power, signal failure, or poor data quality that prevents a DVL from achieving an altitude and bottom lock. Poor data quality can result from an intrinsic problem with the ROV, DVL, improper settings or environmental factors.

DVL problems can lead to other system issues such as the inability to use Auto Depth or Navigation for tracking or dynamic positioning.

DVL diagnostic tools include the HDVL hardware LED status indicator, Greensea Altitude display, DVL Lock Indicator and Alarm, Diagnostics Panel (Vehicle Sensors tab), Advanced Diagnostics Panel (Process View tab) and the browser interface (192.168.1.50), flighthack tools and a multimeter.

Diagnostic Table

If unable to resolve a problem, contact VideoRay Support and report efforts and results.

Issue	Items to Check	Status / Resolution
Lack of power	Check DVL cable.	Reconnect or replace cable.
	Check Hardware status LED.	Reconnect or replace cable.
	Check power from communications module port.	See communications port connector pinout.
No signal input	Check Greensea diagnostics panel.	Timestamp should be incrementing. If not, stop Greensea, turn off the ROV, turn on the ROV and restart Greensea.
	Check DVL browser interface.	Interface should open and live data appear.
	Check Greensea Advanced Diagnostics panel Process View, nortek_socat_bridge.	Click on checkbox for nortek_socat_bridge and check data stream.
Navigation Alarm or No Altitude or Bottom Lock	Too low or two high.	Move the ROV to within specified range (0.2 m to 75* m). * Currently limited to about 30 m.
	Check for physical obstructions.	Clear obstruction.
	Check for cavitation bubbles.	Dive the ROV and move forward to clear bubbles Reduce thruster action while on the surface to reduce cavitation.
	Check browser interface (data view).	Verify good data on all four beams.
	Check browser interface (Bottom Track Data).	Set Bottom Track Data to "DF21 DVL BT Binary".
	Check for environmental interference.	Some bottom types, particularly heavy vegetation may reduce signal quality. Move the ROV to a new location.
	Check for environmental interference.	Make sure there are no acoustic sources nearby.
Incorrect tracking direction	Check DVL orientation setting in the DVL browser interface.	Set DVL orientation to 180 degrees.