The simplest testers for installations that transport Ethernet are verifiers: wiring testers with different functions. Our CableMaster devices are testers for checking the correct placement and for searching for wiring faults. In addition to the cabling test, the higher-quality models also offer simple network diagnostics functions and various power-on tests, such as acoustic cable viewfinders and simple link pulse generators to allow the link LEDs on the switches to flash. "Professional" cabling testers can also connect to the network, either via DHCP or fixed addressing. As soon as they are part of the active network, scan, ping and traceroute functions are available for commissioning and troubleshooting. Also important is the possibility to perform PoE load tests according to IEEE 802.3 af/at/bt to ensure the remote power supply of terminal devices.