The Gemini Multibeam imaging sonar from Tritech is available with Ethernet or VDSL communication protocols. To support these protocols, Tritech has a range of optional interface units for topside connection of the Gemini sonar. Where a fibre-optic multiplexer is present the Gemini will most likely be operated in Ethernet mode. In this situation an interface unit is not required. However, to bench test the sonar the basic Ethernet interface unit simplifies the process and it is supplied with a suitable test cable.

In the event that the Gemini sonar is part of an installation where the communication conductors are copper, the recommended solution is to utilise the VDSL protocol. The VDSL configuration has two interface options and the user should select the one most suited to the installation.

The basic VDSL interface unit is for use on an installation which can directly supply the DC power required to operate the Gemini sonar (this is a typical ROV installation, where the power is supplied from the ROV). The basic VDSL interface can also be used to bench test the Gemini sonar using the short length of test cable, as supplied with the unit.

Where DC power cannot be locally supplied to  the Gemini sonar the Tritech 72V VDSL interface unit is typically used, providing a power source suitable to run over a cable up to 300m in length.