Connecting the Communication Hub cables
The Communication Hub interfaces with the Camera Unit, the DFS75 Sonar Head, and with the topside units via the third-wire trawl cable. The Communication Hub is installed inside the Trawl Unit’s Deployment Pack.
Prerequisites
•  Dow Corning® 4 electrical insulating compound
•  Anti-seize compound
Context
You can access the Communication Hub through the opening in the front of the Trawl Unit’s Deployment Pack.
Note
Later models of the Communication Hub have a sacrificial anode on the end cap and have connectors that are labelled for your convenience. An earlier model with a yellow thermoplastic sleeve covering the pressure housing is shown here.
Image
A Pigtail connector
B Camera connector
C Auxiliary 1 connector for DFS75 Sonar Head
D Auxiliary 2 connector (for optional second sensor system)
E Indicator light for high voltage
Tip
When mating the cable connectors, push all the air out of the connection (you will hear a pop).
To avoid bending the pins, do not twist the cable connector when mating.
Make sure that you tighten the connectors properly.
Procedure
1 Grease all the Communication Hub connectors with a light coating of insulating compound.
2 Apply anti-seize compound to all stainless steel threading.
3 Connect the third-wire deck cable to the Communication Hub.
a Slip your third-wire pigtail cable under the DFS75 Sonar Head.
Don’t bend the cable too tightly.
b Connect the third-wire pigtail cable to the two-pin pigtail connector (A).
4 Connect the Camera Unit’s fourth-wire cable to the camera connector (B) on the Communication Hub.
The camera connector is opposite the pigtail connector and has a blue locking sleeve.
5 Connect the DFS75 Sonar Head to the Communication Hub.
a On the DFS75 Sonar Head, locate the green cable with the connector.
This cable is the power and telemetry cable for the Sonar Head.
b Connect the green cable to the Auxiliary 1 connector on the Communication Hub (C).
6 Connect a dummy plug onto the Auxiliary 2 connector (D).