发明名称 |
Communication system and method |
摘要 |
The present invention relates to a circuit which is connected by two conductors to a control system for a variable analog DC input and that also enables bidirectional digital communication along the two conductors for diagnostic operations of an instrument. The novel circuit includes a switch circuit that has a first position that provided the ability to accept both the variable DC analog signals and the bidirectional digital communication signals by presenting a first impedance for the DC signals and a second switch position for providing a second substantially higher impedance while using the same two conductor system. The novel invention also includes an auxiliary analog input signal to the circuit which allows further control as a current feedback to a control algorithm in a microcontroller. An auxiliary process transmitter can sense pressure, temperature, flow or some other process related variable and couple it to the circuit for control of the instrument. Finally, the novel invention includes a novel voltage regulator and a capacitive voltage supply for utilizing the voltage on the two conductors from the controller to also power the device.
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申请公布号 |
US5684451(A) |
申请公布日期 |
1997.11.04 |
申请号 |
US19950529321 |
申请日期 |
1995.09.18 |
申请人 |
FISHER CONTROLS INTERNATIONAL, INC. |
发明人 |
SEBERGER, STEPHEN G.;GRUMSTRUP, BRUCE F.;GASSMAN, GEORGE W. |
分类号 |
H04L5/14;G08C19/02;(IPC1-7):H04M11/04 |
主分类号 |
H04L5/14 |
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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