Abstract A communication apparatus inserted in parallel in a two-wire communication line of a two-wire measuring instrument which consists of a transmitter and a receiver connected to each other through the two-wire communication line and transmits a process value detected by the transmitter to the receiver as an analog signal, the communication apparatus being adapted to communicate with the transmitter, comprising a switching device for separating a closed loop constituted by the transmitter and the receiver into a first loop including the transmitter and a second loop including the receiver, a power source for supplying power to the transmitter in the first loop, and dummy output means for outputtting a dummy signal to the receiver in the second loop.
Inventors
👤 Koichi Kajiura
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-03 19:37
CPC Classifications
G; G08; G08C; G08C19/00; G08C19/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
117 words
A communication apparatus inserted in parallel in a two-wire communication line of two-wire measuring instrument, which consists of a transmitter and a receiver connected to each other through said two-wire communication line and transmits a processed amount detected by said transmitter to said receiver as an analog signal, said communication apparatus being adapted to communicate with said transmitter, comprising switching means for separating a closed loop constituted by said transmitter and said receiver into a first loop including said transmitter and a second loop including said receiver, a power source for supplying power to said transmitter in said first loop, and a dummy output means for outputting a dummy signal to said receiver in said second loop.
Claim 2
Dependent Claim
117 words
A communication apparatus inserted in parallel in a two-wire communication line of two-wire measuring instrument, which consists of a transmitter and a receiver connected to each other through said two-wire communication line and transmits a processed amount detected by said transmitter to said receiver as an analog signal, said communication apparatus being adapted to communicate with said transmitter, comprising switching means for separating a closed loop constituted by said transmitter and said receiver into a first loop including said transmitter and a second loop including said receiver, a power source for supplying power to said transmitter in said first loop, and a dummy output means for outputting a dummy signal to said receiver in said second loop.
Claim 3
Dependent Claim
26 words
A communication apparatus as set forth in claim 1 wherein said switching means includes a pair of switching devices for establishing said first and second loops.
Claim 4
Dependent Claim
17 words
A communication apparatus as set forth in claim 1 wherein said output means includes a sample-and-hold means.