Signal testing apparatus; connection testing apparatus; cable testing apparatus; electrical testing equipment, namely, continuity testers; cable locators; fibre optic scopes; tone generator cable locators; amplifier probes; wiring verifiers, and patch cable testers; testers used to test and certify new and existing data cabling and networks; testers used to verify the integrity of data cable in a passive network as well as network layer connectivity for an active network, perform length measurements and cable tracing, and detect port services; testers for closed circuit television (CCTV) cameras; PTZ (pan, tilt, zoom) analyser, video generator and programmer for CCTV cameras; testers for digital CCTV cameras that can program the cameras and provide PTZ control via a web interface; testers for digital CCTV cameras that can pass PoE (Power over Ethernet) from a network, through the tester, to the camera or can provide PoE to the camera from the tester's internal battery; testers for digital CCTV cameras that can analyse the video streams of multiple cameras and provide statistics about those streams; data transmission test instruments that prove the performance of data cabling and active networks to international standards; PoE (Power over Ethernet) testers to troubleshoot PoE connectivity issues; testers to verify, troubleshoot and manage industrial ethernet networks; fibre testers including OTDR testers (tier 2), fibre cable certifiers (tier 1), power source and light meter testers, fibre inspection probes and fibre visual fault locators.;