Gemini 720i Product Manual page 67

Troubleshooting
Update rate is slow and there are sometimes large gaps between
pings
VDSL System - The VDSL link is susceptible to electrical noise induced by turning other
devices on and off such as thrusters on an ROV. If the link keeps going down try using the
"Medium Noise" or "High Noise" VDSL setting in the advanced option. Higher Noise settings
trade off speed for reliability of the network link. This may reduce the ping rate slightly but the
link will be more reliable in the presence of noise. Check all connectors on the VDSL twisted
pair, poor contacts have been known to cause this issue.
Ethernet System – There may be noise induced onto the Ethernet cables, be sure to route
these as far away as practicable from noise sources.
All Systems – Some poor quality PC network cards have problems with the large data rate
from the Gemini sonar and drop a significant amount of packets. If you have large packet
loss, try updated network card drivers and a different brand of network card. Also check that
the PC and graphics chipset meet the minimum spec.
Velocimeter reports unrealistic speed of sound
This is often caused by bubbles forming on the metal faces at the front of the sonar,
particularly if the sonar has been stationary for an extended period of time in a tank. Wiping
the surface to remove bubbles should resolve the issue.
Document: 0685-SOM-00001, Issue: 11
Note
The sonar will only respond to ping requests from IP addresses on the same
subnet as the sonar. Some firewalls have been known to cause this issue. To
view the computers routing table type "route print" from the command line.
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Gemini Imaging Sonar
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