Auto-detect system and method for data communication

• US 5,553,271 A
• Filed: 07/11/1994
• Issued: 09/03/1996
• Est. Priority Date: 07/11/1994
• Status: Expired due to Term

• Current Assignee: Hilgraeve, Inc. (KKR & Co., Inc.)
• Original Assignee: Hilgraeve, Inc. (KKR & Co., Inc.)
• Inventors: Ward, Michael R., Hile, John K.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): FREJD, RUSSELL WARREN
• Application Number:
  US08/273,481
• Time in Patent Office: 785 Days
• Field of Search: 340/172.5, 364/200, 370/94, 235/435, 379/67, 395/500
• US Class Current: 703/27
• CPC Class Codes: G06F 13/107 Terminal emulation

Abstract

A method and system which is adapted to receive a data stream, and test a series of multiple-bit sequences from this data stream against a plurality of different character forming criteria until both of the following events have occurred. Specifically, a predetermined number of the multiple-bit sequences must be received and tested, and a predetermined mix of multiple-bit sequences satisfying at least two of the character forming criteria must be received and tested. Once both of these events have occurred, then a data word format is determined from the results of this testing, and the computer is configured to interpret and output characters from the data stream in accordance with this data word format setting. The characters interpreted from the data stream are also tested against a plurality of terminal emulation criteria until a character sequence has been detected which is indicative of only one emulation standard.

Claims

1. A method of automatically configuring the communication settings of a computer to interpret a data stream without requiring any advance knowledge of the word format used to transmit said data stream or the information contained in said data stream, comprising the steps of:

defining a first word format wherein a unit of information is represented by a plurality of bits, the most significant bit being a parity bit of a first polarity;

defining a second word format wherein a unit of information is represented by a plurality of bits, the most significant bit being a parity bit of a second polarity;

.

defining a third word format wherein a unit of information is represented by a plurality of bits, the most significant bit having no parity bit significance;

receiving said data stream by said computer;

testing a series of multiple-bit sequences from said data stream against said first, second and third defined word formats until a predetermined number of said multiple-bit sequences have been received and tested and a predetermined mix of multiple-bit sequences satisfying at least two of said defined word formats have been received and tested;

determining a data word format setting from the results of said testing step; and

configuring said computer to interpret said data stream in accordance with said data word format setting.

2. The invention according to claim 1, further including the step of testing characters interpreted from said data stream against a plurality of terminal emulation criteria until a character sequence has been detected which is indicative of only one terminal emulation standard.

10. The invention according to claim 1, wherein step of determining a data word format setting from the results of said testing step includes:

(a) reading a unit from the data stream and testing a most significant bit against remaining bits to determine which of the first and second word formats is not satisfied by the unit and storing data recording that the word format was not satisfied by the unit;

(b) repeating step (a) for successive units until conditions exercising both first and second word formats have occurred and until a predetermined number of units has been read and tested;

(c) after conditions exercising both first and second word formats have occurred and after a predetermined number of units has been read and tested, determining the stream to be one of said word formats as follows;

(d) determining the data stream to be of the third word format if said first and second word formats were recorded as not satisfied in step (a);

(e) determining the data stream to be of the first word format if only said second word format was recorded as not satisfied in step (a);

(f) determining the stream to be of the second word format if only said first word format was recorded as not satisfied in step (a).

3. A system for automatically configuring the communication settings of a computer to interpret a data stream without requiring any advance knowledge of the word format used to transmit said data stream or the information contained in said data stream, comprising:

interface means for receiving a data stream;

first processing means for defining a first word format wherein a unit of information is represented by a plurality of bits, the most significant bit being a parity bit of a first polarity, said first processing means also defining a second word format wherein a unit of information is represented by a plurality of bits, the most significant bit being a parity bit of a second polarity, said first processing means also defining a third word format wherein a unit of information is represented by a plurality of bits, the most significant bit having no parity bit significance;

second processing means for testing a series of multiple-bit sequences from said data stream against said first, second and third defined word formats until a predetermined number of said multiple-bit sequences have been received and tested and a predetermined mix of multiple-bit sequences satisfying at least two of said defined word formats have been received and tested;

third processing means for determining a data word format setting from the results of said second processing means; and

storage means for configuring said computer to interpret said data stream in accordance with said data word format setting.

4. The invention according to claim 3, further including fourth processing means for testing characters interpreted from said data stream against a plurality of terminal emulation criteria until a character sequence has been detected which is indicative of only one terminal emulation standard.

5. The invention according to claim 4, wherein said fourth processing means includes a state machine which includes a plurality of levels for determining when a character sequence has been detected which is indicative of only one terminal emulation standard.

6. The invention according to claim 3, wherein said data stream is a serial data stream, which has been received from another computer.

7. The invention according to claim 6, wherein said interface means includes a modem and a buffer for temporarily holding said data stream until all of said testing has been completed.

11. The invention according to claim 3, wherein said third processing means determines a data word format setting from the results of said testing step by:

(a) reading a unit from the data stream and testing a most significant bit against remaining bits to determine which of the first and second word formats is not satisfied by the unit and storing data recording that the word format was not satisfied by the unit;

(b) repeating step (a) for successive units until conditions exercising both first and second word formats have occurred and until a predetermined number of units has been read and tested;

(c) after conditions exercising both first and second word formats have occurred and after a predetermined number of units has been read and tested, determining the stream to be one of said word formats as follows;

(d) determining the data stream to be of the third word format if said first and second word formats were recorded as not satisfied in step (a);

(e) determining the data stream to be of the first word format if only said second word format was recorded as not satisfied in step (a);

(f) determining the stream to be of the second word format if only said first word format was recorded as not satisfied in step (a).

8. A method of automatically configuring the communication settings of a computer to interpret a data stream without requiring any advance knowledge of the word format used to transmit said data stream or the information contained in said data stream, comprising the steps of:

receiving said data stream by said computer;

defining a first word format wherein a unit of information is represented by a plurality of bits, the most significant bit being a parity bit of a first polarity;

defining a second word format wherein a unit of information is represented by a plurality of bits, the most significant bit being a parity bit of a second polarity;

defining a third word format wherein a unit of information is represented by a plurality of bits, the most significant bit having no parity bit significance;

testing a series of multiple-bit sequences form said data stream against at least one of said first, second and third defined word formats;

determining at least an interim data word format setting from the results of said testing step after at least two multiple-bit sequences have been received which have potential for meeting two of said defined word formats; and

causing said computer to transmit data streams in accordance with said interim data word format setting.

9. A method of automatically configuring the communication settings of a computer to emulate one of a plurality of computer terminal types without requiring any advance knowledge of the communication settings used to transmit data or the information contained in said data, comprising the steps of:

receiving a data stream by said computer;

interpreting the presence of characters from multiple-bit sequences in said data stream;

processing combinations of said interpreted characters through a state machine having a plurality of different table levels that progress toward the identification of a unique emulation mode;

causing said computer to execute combinations of said interpreted characters which satisfy one of a plurality of emulation modes that satisfy said combinations until a unique emulation mode has been determined;

determining a unique emulation mode from the results of said processing step; and

causing said computer to lock in said determined emulation mode.