Computer networking apparatus

• US 5,057,829 A
• Filed: 03/02/1989
• Issued: 10/15/1991
• Est. Priority Date: 03/02/1989
• Status: Expired due to Fees

• Current Assignee: Secom Information Products Company
• Original Assignee: Secom Information Products Company
• Inventors: Velazquez, Juan F.
• Primary Examiner(s): Weldon, Ulysses
• Application Number:
  US07/318,123
• Time in Patent Office: 957 Days
• Field of Search: 375/7, 375/8, 455/78, 340/825, 340/825.03, 340/825.06, 340/825.5, 340/825.51, 340/310 R, 340/310 A, 370/85.1, 370/85.6, 332/100, 328/165, 328/167, 377/50, 377/56, 377/114
• US Class Current: 370/465
• CPC Class Codes: G06F 13/4072 Drivers or receivers G06F13/4086 takes precedence; for multistate logic circuits H03K19/0002

Abstract

An adjustment free computer networking apparatus is shown which isolates the transmitter portion thereof from the power line when it is not transmitting, has a carrier isolator provided within its power supply to prevent it from shorting out its own signal, and which has a crystal oscillator to maintain the frequency of the signals being used to transmit data.

Claims

1. A computer networking apparatus including, in combination:

(a) means to connect to a computer comprising an RJ45 interface;

(b) means to accept data from a computer comprising an RS232C interface;

(c) means to transmit said data over an AC power line including a transmit logic connected to said means to accept, a variable module counter connected to said transmit logic, a crystal oscillator connected to said variable module counter, a DC level signal conditioner connected to said variable module counter and said transmit logic, a low pass filter connected to said DC level signal conditioner, a transmit amplifier connected to said low pass filter and said transmit logic, and an interface circuit connected to said AC power line and said transmit amplifier;

(d) means to receive data from an AC power line including an interface circuit connected to said AC power line, a band pass filter and limiting amplifier connected to said interface circuit, and an automatic level control module connected to said band pass filter and limiting amplifier;

(e) means to process said data received including a Schmitt trigger connected to said to automatic gain control module, a frequency detector connected to said crystal oscillator and said Schmitt trigger, a carrier sense logic connected to said frequency detector, an address decoder connected to said frequency detector and said carrier sense logic, and a transmit register and address clock logic connected to said address decoder and said frequency detector;

(f) means to decode said data received; and

(g) means to transfer said decoded data to said computer.

2. The device claimed in claim 1, wherein the means to transfer said data to said computer includes:

(a) a receive logic connected to said transmit register and address clock logic, said address decoder, and said frequency detector, said receive logic also being connected to said means to accept data.

3. The device claimed in claim 1, further including:

(a) a power supply connected to said AC power line;

(b) a carrier isolator interposed between said power supply and said AC power line.

4. A computer networking apparatus including, in combination:

(a) means to connect to a computer;

(b) means to accept data from a computer;

(c) means to transmit said data over an AC power line including a transmit logic connected to said means to accept, a variable module counter connected to said transmit logic, a crystal oscillator connected to said variable module counter, a DC level signal conditioner connected to said variable module counter and said transmit logic, a low pass filter connected to said DC level signal conditioner, a transmit amplifier connected to said low pass filter and said transmit logic, and an interface circuit connected to said AC power line and said transmit amplifier;

(d) means to receive data from an AC power line including an interface circuit connected to said AC power line, a band pass filter and limiting amplifier connected to said interface circuit, and an automatic level control module connected to said band pass filter and limiting amplifier;

(e) means to process said data received including a Schmitt trigger connected to said to automatic gain control module, a frequency detector connected to said crystal oscillator and said Schmitt trigger, a carrier sense logic connected to said frequency detector, an address decoder connected to said frequency detector and said carrier sense logic, and a transmit register and address clock logic connected to said address decoder and said frequency detector;

(f) means to decode said data received; and

(g) means to transfer said decoded data to said computer.

5. The device claimed in claim 4, wherein the means to transfer said data to said computer includes:

(a) a receive logic connected to said transmit register and address clock logic, said address decoder, and said frequency detector, said receive logic also being connected to said means to accept data.

6. The device claimed in 4 further including:

(a) a power supply connected to said AC power line; and

(b) a carrier isolator interposed between said power supply and said AC power line.