发明名称 |
Private automatic business exchange |
摘要 |
The invention interfaces a two-wire line to many smart terminals, modems or telephones only one of which is in use at a time. The invention is used by electric utilities in substations to automatically transfer stored data originating in the substation to a central control room.
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申请公布号 |
US5070523(A) |
申请公布日期 |
1991.12.03 |
申请号 |
US19890355413 |
申请日期 |
1989.05.22 |
申请人 |
DA-TEL RESEARCH CO., INC. |
发明人 |
HAFER, GEORGE F.;RATTAN, LANHAM P. |
分类号 |
H04M3/527;H04M11/00 |
主分类号 |
H04M3/527 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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