| 摘要 |
PORTABLE TESTING DEVICE FOR MONITORING COMMUNICATION LINE ACTIVITY This invention relates to a portable testing device which is used in a system having a host terminal, a plurality of secondary terminals, and a communication line interconnecting the host and secondary terminals for in-house communication. The transmission line includes a transmit line pair, a receive line pair, and a ground line. The testing device is operated in one of three modes which are selected via a switch on the device. The three modes of operation are: 1) Monitoring the transmit lines from the host and secondary terminals; 2) Performing "turn-around" functions with the host or secondary terminals; and 3) Performing "turn-around and load testing" with the host or secondary terminals. |
