Encoding technique for enabling a device to process different types of digital information transmitted along a single information channel

• US 3,955,188 A
• Filed: 04/08/1974
• Issued: 05/04/1976
• Est. Priority Date: 01/04/1971
• Status: Expired due to Term

• Current Assignee: Honeywell Information Systems, Inc. (Honeywell International Inc.)
• Original Assignee: Honeywell Information Systems, Inc. (Honeywell International Inc.)
• Inventors: Viswanathan, G. R.
• Primary Examiner(s): Curtis, Marshall M.
• Application Number:
  US05/458,145
• Time in Patent Office: 757 Days
• Field of Search: 340/324 AD, 340/206, 340/168 S
• US Class Current: 345/29
• CPC Class Codes: G06F 3/153 using cathode-ray tubes
• CPC Class Codes: H04J 7/00 Multiplex systems in which the amplitudes or durations of the signals in individual channels are characteristic of those channels
• CPC Class Codes: H04L 25/00 Baseband systems
• CPC Class Codes: H04L 5/1423 for simultaneous baseband signals
• CPC Class Codes: H04N 7/148 Interfacing a video terminal to a particular transmission medium, e.g. ISDN

Abstract

A data processing system includes a first device which transmits different types of pulse coded digital information along a single channel to a second device for separation and distribution to a number of different outputs. The different types of digital information transmitted are encoded with different pulse widths. The pulse widths for the different types of information are selected to provide highly reliable data transmission. The second device includes a receive section which has a plurality of detectors. Each of these detectors operate to detect only the pulse coded digital information encoded with predetermined pulse widths and pass them to its output. The system accommodates bidirectional transmission and processing of the encoded digital information by including like transmit and receive sections within each device.

Claims

1. In a display system including a first unit for transmitting digital information including video character and control information signals to a second unit for use in a cathode ray tube display device, an interconnection system comprising:

a bus directly coupling said first unit to said second unit;

transmit means included within said first unit for applying said video character and control information signals to said bus, each different type of information being pulse coded into groups of coded pulses having the same pulse width with a predetermined one of a plurality of different pulse widths; and

,

receive means included within said second unit coupled to said bus for separating said video characters pulses and control pulses on the basis of their pulse widths from said information signals for distribution to a different predetermined one of a number of output terminals included in said device for subsequent processing by different portions of said display device.

2. The system of claim 1 wherein said receive means includes a plurality of detector means, each including input and output means, each of said input means being connected to receive said digital information pulses and each being operative to pass to each said output means only those pulses corresponding to said type of digital information characterized by said predetermined pulse widths.

3. The system of claim 2 wherein said receive means further includes delay means including an input terminal and a plurality of output terminals, each of said output terminals arranged to provide an output pulse delayed from the pulse applied to said input terminal by a different predetermined amount;

each of said detectors including pulse generating means coupled to said detector input means and logic means coupled to predetermined ones of said delay means output terminals and to said pulse generating means, said pulse generating means being operative to generate a pulse having a predetermined pulse width in response to the leading edge of each pulse applied to said detector input and said logic means being coupled to be responsive to said pulses applied to said detector input means and the pulses produced by pulse generating means so as to logically combine them in a manner to pass only digital information pulses having predetermined pulse widths to said detector output means.

4. The system of claim 2 wherein said delay means includes a delay line.

5. The system of claim 3 wherein each of said logic means includes means for receiving a common control input for either enabling or disabling said detectors simultaneously for receive and transmit operations respectively.

6. The system of claim 3 wherein said logic means includes AND gates and said delay means includes a delay line.

7. The system of claim 1 wherein said first unit further includes receive means, said receive means including a plurality of detectors, each including input and output means, each of said input means being connected to receive said digital information pulses and each being operative to pass to each said output means only those pulses corresponding to said type of digital information characterized by predetermined pulse widths;

and,

said second unit includes transmit means for applying to said bus groups of digital data and timing pulses, each coded with different predetermined pulse widths after receiving said video information pulses from said first transmit means whereby said interconnection system provides for bidirectional transmission of said different types of digital information.

8. The system of claim 7 wherein at least first and second detectors of said plurality of detectors of said receive means are connected in series, said input means of said first detector being connected to enable to pass at least two different types of digital information to said second detector, said second detector input means being connected to enable said second detector to pass to said output means only a predetermined one of said two types of digital information.

9. The system of claim 8 wherein said receive means further includes delay means including an input terminal and a plurality of output terminals, each of said output terminals arranged to provide an output pulse delayed from the pulse applied to said input terminal by a different predetermined amount;

each of said detectors including pulse generating means coupled to said detector input means and logic means coupled to predetermined ones of said delay output terminals and to said pulse generating means, said pulse generating means being operative to generate a pulse having a predetermined pulse width in response to the leading edge of each pulse applied to said detector input means and said logic means being coupled to be responsive to said pulses applied to said detector input means and the pulses produced by pulse generating means so as to logically combine them in a manner to pass only digital information pulses having predetermined pulse widths to said detector output means.

10. The system of claim 9 wherein each of said logic means includes means for receiving a common control input for either enabling or disabling said detectors simultaneously.

11. In a display control system including a cluster control device and at least one CRT display device an interconnection network comprising:

first means included within said cluster control unit for transmitting and receiving signals to and from said control unit, said first means including a transmit section (T-100) having a plurality of inputs and at least one output and a receive section (R-100) having at least one input and a plurality of output terminals;

second means included within said display unit for transmitting and receiving signals to and from said display unit, said means including a transmit section (T-200) having a plurality of inputs and at least one output and a receive section (R-200) having at least one input and a plurality of outputs;

a twisted conductor means for directly interconnecting said first means and second means, said first means being enabled by said cluster control unit to condition said transmit section (T-100) to transmit different types of digital information signals including pulse coded video character information and at least two types of pulse coded video control information encoded into groups of coded pulses with different pulse widths the pulses within each group having the same predetermined pulse width in a predetermined sequence and, said second means being enabled by said display unit to condition said receive section (R-200) to detect said video character and video control digital information signals on the basis of pulse widths and distribute said groups of pulses corresponding to each type of information to a predeterined one of said output terminals.

12. The system according to claim 11 wherein said CRT display unit in response to a predetermined type of said video control digital information indicating the end of said information transfer is operative to condition said second means to disable said receive section (R-200) and enable said transmit section (T-200) to transmit timing pulses together with pulse coded bits of a keyboard entered character when stored, each being encoded into groups of pulses with different pulse widths and said cluster control unit being operative to condition said first means upon having transmitted said predetermined type of said video control digital information to disable said transmit section (T-100) and enable said receive section (R-100) to detect said groups of pulses corresponding to said keyboard entered digital information and timing information on the basis of said pulse widths and distribute each type of digital information to a predetermined one of said output terminals for subsequent processing by said cluster control device.

13. In a digital display system including a transmitter station for transmitting digital coded information coded with different pulse widths so as to define video information and at least first and second kinds of control video information, and a receiver station for supplying each different type of digital information signals to different portions of a CRT display unit, an interconnection network comprising:

a bus directly coupling said transmitter station to said receiver station; and

said receiver station including a plurality of detectors, each detector including input means and output means, each of said input means being connected to receive said digital information encoded into groups of coded pulses having the same predetermined pulse width within a range of pulse widths, said pulse width of said first and second kinds of control information each having different ranges of pulse widths, each of said detectors including pulse generating means for generating a pulse whose width defines the type of digital information being detected by the detector selected to process same and, each of said detectors including means for comparing said generated pulse with the transmitted digital information pulses so as to produce a signal at said output means only in response to digital information pulses whose width is within the range of pulse widths characteristic of said type of information detectable by said detector.