Abstract: A telephone station test set performs voltage and polarity checks on four and six wire systems. Both four and six wire jacks are provided which are coupled to LED networks. A switch is provided so that both "intercom" and "data" pairs of a six wire system can be tested by the same LED networks.

Abstract: A multiplexed terminal monitors the status of a plurality of remote SPC telephone switches simultaneously. A computer has at least one I/O port. A serial communication adapter is coupled to the I/O port and provides a plurality of extended I/O ports. The extended ports are coupled through individual channels to remote SPC switches with remote command and display terminal ports. Software controls the computer to multiplex the extended ports and causes data representing the status and identification of each switch to be displayed simultaneously on a display.

Abstract: A one-piece frame arm extender allows telephony terminal blocks to be mounted concurrently on a main distribution frame. The extender does not require any full assembly prior to being able to support itself.