ORTs and DORTs are controlled using a frequency band specific Lightweight Command Unit (LCU) which consists of an over-the-side dunking transducer connected either to a splash-proof handheld terminal or, via supplied software, to any PC. The Type 7663 unit is a Medium Frequency LCU for commanding ORTs whilst the Type 7667 LCU is a Low Frequency unit suitable for use with DORTs

For security of operation, a special coding system provides protection against accidental release by noise or acoustic transmissions from other equipment. Each ORT or DORT has its own unique ‘address’ enabling a number of units to be deployed in the same area without risk of interference.