发明名称 |
Telephone extension switch hook state detection system |
摘要 |
A computer integrated telephony system embodied in a PC that includes a telephony interface connected to the local loop that detects whether one or more extension phones are off-hook by using the signal generating and detection capabilities found on a typical telephony interface card. In the preferred embodiment, the telephony interface is based on a programmable DSP that generates and injects onto the local loop a subsonic signal having a known shape and amplitude. If one or more extensions are off-hook, the amplitude of the subsonic signal detected on the line will be significantly attenuated. The amplitude of the detected signal is compared against a threshold value and an indication is made if the detected signal amplitude is below the threshold value.
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申请公布号 |
US6041107(A) |
申请公布日期 |
2000.03.21 |
申请号 |
US19980070058 |
申请日期 |
1998.04.30 |
申请人 |
AG COMMUNICATION SYSTEMS CORPORATION |
发明人 |
JONES, ERIC A.;DETERING, GREIG R. |
分类号 |
H04M1/723;H04M1/82;(IPC1-7):H04M1/00 |
主分类号 |
H04M1/723 |
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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