Reson Seabat 8101

Options and Upgrades4.14 Option 043, Coax to Fiber-Optic Interface Unit4.14.1 IntroductionThe SeaBat 8101 Sonar Head uplinks data to the Sonar Processor via a co-axialcable embedded in the standard 25 meter head to processor cable. This lengthcan be increased to a maximum of 150 meters by making compensating circuitadjustments in the Sonar Processor. Option 043 allows the use of a fiber-opticcable which provides a far greater length. Fiber-optic interfaces are typically usedwith ROV installations where the head to processor cable is first terminated onthe vehicle.This option requires no modification to the sonar head but does require modificationto the circuitry of the sonar processor. In addition, the sonar head to sonarprocessor cable will require a change in termination dictated by the specifics ofthe customer's installation.For systems that already have Option 043 modifications to the sonar processor,the co-ax to fiber-optic interface unit alone can be procured as Option 043A.4.14.2 InstallationThe fiber optic interface unit (Figure 25) consists of a coax to fiber converter box.The standard head to processor cable must be reterminated within the ROV. Thenormal coaxial uplink is redirected to the coax to fiber-optic interface unit whichwill be located in the general vicinity of the sonar head on the ROV. The opticaloutput of the interface unit must be coupled to the fiber-optic cable in the ROV'sumbilical cable. At the topside end, the fiber-optic cable is sent directly to eitherthe FO1 or FO2 connectors on the rear panel of the sonar processor. The 8101system must be configured to look for the uplink at the selected fiber-optic port.See Paragraph 3.9.1, for information on selecting the correct uplink port.4.14.3 ApplicationDue to the high frequency digital uplink employed by the SeaBat 81xx series systems,uplink cable length is generally limited to 150 meters of coaxial cable. Forinstallations where cable lengths in excess of this length are required, such asROV installations, Option 043 should be used.The Coax to Fiber-Optic Interface Unit is designed to fit into an ROV junctionbox. The unit requires 24 VDC operating power which must be supplied from theROV. Analog co-axial input is made via a standard 75 ohm BNC connector andthe optical output uses as ST type 62.5/125 nm fiber. See Table 9 and Table 10for additional specifications.______________________________________________________________________SeaBat 8101 Operator's Manual 4-14 Version 3.02