| 摘要 |
<p>An LAN parameter-measuring instrument is provided for measuring at least one physical parameter of a wired, packet-based, baseband LAN. The instrument comprises input means (21) for providing a connection to the LAN transmission medium (10) to enable measurements to be made while the LAN is active, and voltage measuring means arranged to connect to the LAN transmission medium (10) through said input means (21) and operative to measure the voltage on the LAN transmission medium during inter-packet gaps. The voltage measuring means may, for example, be in the form of a peak detector or sample-and-hold circuit. The instrument can also be arranged to determine the resistance of the LAN transmission medium (10) by measuring the inter-packet voltage during the injection of a known current into the transmission medium.</p> |
