A modem use monitor (MUM) utilizable with one or more groups of modems is disclosed which modems, in turn, serve a rotary hunt arrangement of telephone lines for data communications. For analytical purposes, for each modem there is an intercept for providing a data carrier detect signal to central processor. The monitoring of the signal is provided on a periodic basis, generally every five seconds, and an indication of such response is provided periodically, generally each minute.
The modems within each group are numbered and have correspondingly numbered registers for storing the responses for each modem in number sequence. The central processor has the additional function of examining the registers upon acquisition of each response and ascertaining if all modems lower in the numbered sequence have an indication of data carrier detect present. The MUM also formulates a histogram for recording all responses for a given period, which histogram shows the modems with data carrier detect present, modems with data carrier detect absent, and modems answering out-of-sequence.
The histogram material is readily interpreted so that modem defects such as a ring no answer condition or lock-up condition can be identified.
April 4, 1989 – 4,819,235 Modem use monitor