Cable pair testing arrangement

Claim 2

Apparatus for testing the pulse transmission characteristics of a cable pair which comprises: means for generating a pseudo-ternary pulse train in accordance with predetermined coding rules, the violation of said rules being indicative of an error in the pulse train, for transmission of said pseudo-ternary pulse train over the cable pair; means for generating an interfering tone signal; level control means operatively connected between said interfering tone signal generating means and said violation detection means to add predetermined levels of the interfering signal with said pseudo-ternary pulse train until violation of the coding rules occurs; and, means for detecting violations in the coding rules of said pulse train and giving indications thereof.

Claim 3

Apparatus in accordance with claim 1 in which the pseudo-ternary pulse train is of a duobinary format.

Claim 4

Apparatus in accordance with claim 1 in which the pseudo-ternary pulse train is of a bipolar signal format.

Claim 5

Apparatus in accordance with claim 3 in which said bipolar signal is pseudo-random.

Claim 6

Apparatus for testing the pulse transmission characteristics of a cable pair which comprises: a cable pair; pulse generating means operatively connected to one end of said cable pair, said pulse means generating a pseudo-random, pseudo-ternary pulse train in accordance with predetermined coding rules, the violation of said rules being indicative of an error in the pulse train, for transmission over the cable pair; pulse reconstructing means having an input connected to receive the pseudo-ternary pulse train transmitted over said cable pair, and having an output; means for generating an interfering signal; level control means operatively connected between the interfering signal and the output of the reconstructing means so that controlled amounts of interfering signal are added to the reconstructed pseudo-ternary signal until violation of the coding rules occur; code violation detecting means having an output, and having an input operatively connected to receive the combined outputs from the pulse reconstructing means and said level control means; and, indicating means having an input connected to the output of said detecting means for indicating when said code violations occur.

Claim 7

Apparatus for testing the pulse transmission characteristics of a cable pair which comprises: a cable pair; pulse generating means operatively connected to one end of said cable pair, said pulse means generating a pseudo-random, pseudo-ternary pulse train in accordance with predetermined coding rules, the violation of said rules being indicative of an error in the pulse train, for transmission over the cable pair; pulse reconstructing means having an input connected to receive the pseudo-ternary pulse train transmitted over said cable pair, and having an output; means for generating an interfering signal; level control means operatively connected between the interfering signal and the output of the reconstructing means so that controlled amounts of interfering signal are added to the reconstructed pseudo-ternary signal until violation of the coding rules occur; code violation detecting means having an output, and having an input operatively connected to receive the combined outputs from the pulse reconstructing means and said level control means; and, indicating means having an input connected to the output of said detecting means for indicating when said code violations occur.

Claim 8

Apparatus according to claim 5 wherein said pseudo-ternary pulse generating means further comprises: means for generating a pseudo-random binary pulse train; and, means for converting the pseudo-random binary pulse train into a duobinary pulse train.

Claim 9

Apparatus according to claim 6 wherein said reconstructing means further comprises: amplifier means having an input and an output; and, equalizer means operatively connected between the input of the pulse reconstructing means and the input of the amplifier means.

Claim 10

Apparatus according to claim 5 wherein said pseudo-ternary pulse generating means further comprises: means for generating a pseudo-random binary pulse train; and, means for converting the pseudo-random biNary pulse train into a pseudo-random bipolar pulse train.

Claim 11

Apparatus according to claim 8 wherein said reconstructing means further comprises: amplifier means having an input and an output; and, equalizer means operatively connected between the input of the reconstructing means and the input of the amplifier means.

Claim 12

Apparatus according to claim 9 wherein said pseudo-ternary pulse generating means further comprises: pseudo-random binary word generating means; and, timing means having an output connected to provide timing information to said word generating means, said timing means developing a timing signal having a rate equal to the pulse rate of the pseudo-random bipolar pulse train.

Claim 13

Apparatus according to claim 10 wherein said equalizer means is manually adjustable.

Claim 14

Apparatus according to claim 10 wherein said equalizer means is automatically adjustable.

Claim 15

Apparatus according to claim 12 wherein said reconstructing means further comprises: amplitude limiting means having an input and having an output connected to the input of said equalizer means; and, impedance matching means having an input connected to the output of said cable pair, and an output connected to the input of said amplitude limiting means.

Claim 16

Apparatus for determining the pseudo-ternary pulse transmission performance of a cable pair which comprises: means for reconstructing the received pseudo-ternary pulse train so that pulse, no-pulse decisions can be made, said reconstructing means having an input for connection to the receiving terminals of the cable pair, and an output; means for generating an interfering signal; level control means operatively connected between the interfering signal and the output of the reconstructing means so that controlled amounts of interfering signal may be combined with the reconstructed pseudo-ternary pulse train until errors occur; means for detecting errors in the pseudo-ternary pulse train, said error detector having an input operatively connected to receive the combined interfering signal and reconstructed pseudo-ternary pulse train, and an output; and, error indicating means having an input connected to the output of said error detecting means.

Claim 17

Apparatus for determining the pseudo-ternary pulse transmission performance of a cable pair which comprises: means for reconstructing the received pseudo-ternary pulse train so that pulse, no-pulse decisions can be made, said reconstructing means having an input for connection to the receiving terminals of the cable pair, and an output; means for generating an interfering signal; level control means operatively connected between the interfering signal and the output of the reconstructing means so that controlled amounts of interfering signal may be combined with the reconstructed pseudo-ternary pulse train until errors occur; means for detecting errors in the pseudo-ternary pulse train, said error detector having an input operatively connected to receive the combined interfering signal and reconstructed pseudo-ternary pulse train, and an output; and, error indicating means having an input connected to the output of said error detecting means.

Claim 18

Apparatus according to claim 14 wherein said level control means is calibrated to measure the eye degradation factor.

Claim 19

Apparatus according to claim 15 wherein said interfering signal generating means is a tone source having a frequency which is approximately one-fourth the bit rate of the pulse train.

Claim 20

Apparatus for testing the pulse transmission tolerance of a transmission path which comprises: means for generating a pseudo-random, pseudo-ternary pulse train in accordance with predetermined coding rules, for transmission over said path, the violation of said rules being indicative of an error in the pulse train; pulse reconstruction means having an output, and having an input for operative connection to the receiving end of the transmission path, said reconstructing means accepting the transmitted pseudo-ternary pulse train and providing a reconstructed pseudo-ternary pulse train at said output; means for detecting coding rule violations in said regenerated pulse train and giving indications thereof; means for generating an interfering signal; level control means operatively connected between said interfering signal generating means and said detecting means to add selected levels of the interfering signal in the range of 0 to one-half the amplitude of a pulse in said reconstructed pulse train, said control means being calibrated to indicate the transmission tolerance when the interfering signal amplitude is adjusted to the level at which errors occur.

Claim 21

Apparatus for testing the pulse transmission tolerance of a transmission path which comprises: means for generating a pseudo-random, pseudo-ternary pulse train in accordance with predetermined coding rules, for transmission over said path, the violation of said rules being indicative of an error in the pulse train; pulse reconstruction means having an output, and having an input for operative connection to the receiving end of the transmission path, said reconstructing means accepting the transmitted pseudo-ternary pulse train and providing a reconstructed pseudo-ternary pulse train at said output; means for detecting coding rule violations in said regenerated pulse train and giving indications thereof; means for generating an interfering signal; level control means operatively connected between said interfering signal generating means and said detecting means to add selected levels of the interfering signal in the range of 0 to one-half the amplitude of a pulse in said reconstructed pulse train, said control means being calibrated to indicate the transmission tolerance when the interfering signal amplitude is adjusted to the level at which errors occur.

Claim 22

Apparatus in accordance with claim 17 wherein said interfering signal generating means is a tone source having a frequency which is approximately one-fourth the bit rate of the pulse train.