EP0239731A2
Expired / Lapsed
EP
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Differential transceiver with line integrity detection
Assignee: International Business Machines Corp
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Filing: 1987-01-23
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Granted: —
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Expires: 2007-01-23
Abstract
Abstract A differential transceiver transmission line integrity detector detects both open and short circuits in the transmission lines (12,14). The two transmission lines are terminated at both ends by selected impedances. A driver (30, 32) coupled to each of the transmission lines drives the lines with data signals. Signal levels on the lines are detected and compared with expected levels to generate line integrity indications. Both open and short conditions are detected and indicated by the line integrity indications.
Inventors
- 👤 Anthony Richard Bonaccio
- 👤 Brent Allen Carlson
- 👤 Lloyd Stephen Heim
- 👤 Kenneth Ardell Moe
- 👤 Steven Alois Schmitt
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 00:44
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/08; H04L25/085
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
151 words
An open line detector in a differential transceiver having a receiver connected to at least a pair of transmission lines (12, 14à) for receiving data signals on the lines and a transmitter connected to the same pair of transmission lines for transmitting data signals on the lines, each line having predetermined conductive properties, characterized in that it comprises: first comparing means (34) coupled to a first reference signal and to one of the lines (12) for comparing the data signals on the line to the first reference signal; and second comparing means (36) coupled to a second reference signal and to the other one of the lines (14) for comparing the data signals on the line to the second reference signal, wherein a substantial reduction of the data signal conductive properties of at least one of the lines causes the comparator means coupled to said line to provide a positive comparison.
Claim 2
Dependent Claim
151 words
An open line detector in a differential transceiver having a receiver connected to at least a pair of transmission lines (12, 14à) for receiving data signals on the lines and a transmitter connected to the same pair of transmission lines for transmitting data signals on the lines, each line having predetermined conductive properties, characterized in that it comprises: first comparing means (34) coupled to a first reference signal and to one of the lines (12) for comparing the data signals on the line to the first reference signal; and second comparing means (36) coupled to a second reference signal and to the other one of the lines (14) for comparing the data signals on the line to the second reference signal, wherein a substantial reduction of the data signal conductive properties of at least one of the lines causes the comparator means coupled to said line to provide a positive comparison.
Claim 3
Dependent Claim
40 words
The open line detector of claim 1 characterized in that each transmission line comprises a first end and a second end and wherein the first and second ends of each line are terminated with predetermined impedances (16, 18, 20, 22).
Claim 4
Dependent Claim
21 words
The open line detector of claim 2 characterized in that the termination impedances are resistors having resistances of approximately equal value.
Claim 5
Dependent Claim
31 words
The open line detector of claim 3 characterized in that the transmission lines are biased with potentials having opposite polarity, said potentials being small compared to the potential of the data.
Claim 6
Dependent Claim
38 words
The open line detector of any one of claims 1-4 wherein the transmitter comprises a pair of balanced drivers (30, 32) coupled to the lines for driving a predetermined current on said lines representative of the data signals.
Claim 7
Dependent Claim
39 words
The open line detector of claim 5 characterized in that the first and second reference signals are selected to exceed the potential across the termination resistors when the respective drivers drive the lines in the direction of their biasing.
Claim 8
Dependent Claim
50 words
The open line detector of claim 6 characterized in that the reference signals are selected to not exceed the potential across at least one of the termination resistors when an open condition exists on a line such that the comparing means coupled to said open line provides the positive comparison.
References Cited (Backward Citations)
No citation records indexed.
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