HDLC asynchronous to synchronous converter

Claim 2

In a communications network having at least two stations, with one of said two stations being able to communicate asynchronously while the other station being able to communicate synchronously and each station having a system unit coupled to a communications device, interconnected by a transmission network a device for incorporating in the one of said two stations communicating asynchronously so that said one of said two stations communicating asynchronously can communicate with the other station communicating synchronously, said device comprising: an interface means disposed between the system unit and the communications device said interface means receiving data arranged on byte boundaries from the system unit and passing said data asynchronously to the communications device, a first means for receiving a synchronous frame from an application program being executed on the one of said two stations communicating asynchronously and for converting said synchronous frame into an asynchronous frame to allow transmission through the interface means; and a second means for receiving the asynchronous frame from the interface means, converting the asynchronous frame to a synchronous frame and transmitting the synchronous frame through the transmission network to the other station which communicates synchronously.

Claim 3

The device of claim 1 wherein the interface means includes a COMM Port.

Claim 4

The device of claim 2 wherein the interface means includes a Universal Asynchronous Receiver/Transceiver (UART).

Claim 5

In a communications network having at least two stations, with one of said two stations being able to communicate asynchronously and the other station being able to communicate synchronously, interconnected by a transmission network a device for incorporating in the one of said two stations communicating asynchronously so that said one of said two stations communicating asynchronously can communicate with the other station communicating synchronously, said device comprising: a COMM port located in the one of said two stations communicating asynchronously; a first means for receiving a frame formatted in accordance with a first protocol, from an application program being executed on the one of said two stations communicating asynchronously and for converting said frame to a second protocol before transmitting the frame through the COMM port; and a second means for receiving the frame from the COMM port, reformatting the frame in accordance with the first protocol before transmitting the frame, through the transmission network to the other station which communicates synchronously.

Claim 6

In a communications network having at least two stations, with one of said two stations being able to communicate asynchronously and the other station being able to communicate synchronously, interconnected by a transmission network a device for incorporating in the one of said two stations communicating asynchronously so that said one of said two stations communicating asynchronously can communicate with the other station communicating synchronously, said device comprising: a COMM port located in the one of said two stations communicating asynchronously; a first means for receiving a frame formatted in accordance with a first protocol, from an application program being executed on the one of said two stations communicating asynchronously and for converting said frame to a second protocol before transmitting the frame through the COMM port; and a second means for receiving the frame from the COMM port, reformatting the frame in accordance with the first protocol before transmitting the frame, through the transmission network to the other station which communicates synchronously.

Claim 7

The device of claim 4 wherein converting to the frame received from the application program by the first means includes encapsulating the frame with a pair of flag fields, with each flag field containing a first set of predetermined bits and inserting one or more "0" bits in information contained between the flag fields so that the set of predetermined bits is not repeated in the information contained between the flag fields.

Claim 8

In a communications network having at least two stations, with one of said two stations being able to communicate asynchronously while the other station being able to communicate synchronously and each station having a system unit coupled to a communications device, interconnected by a transmission network a device for incorporating in the one of said two stations communicating asynchronously so that said one of said two stations communicating asynchronously can communicate with the other station communicating synchronously, said device comprising: an interface means disposed between the system unit and the communications device said interface means receiving data arranged on byte boundaries from the system unit and passing said data asynchronously to the communications device; a first means for receiving a synchronous information frame from an application program being executed on the one of said two stations communicating asynchronously and for modifying said frame to allow transmission through the interface means; and a second means for receiving the frame from the interface means, searching the frame for sequences of predetermined bit patterns and substituting different sequences of bit patterns which makes the frame compatible for transmission, using a synchronous protocol, through the transmission network to the other station which communicates synchronously.

Claim 9

In a communications network having at least two stations, with one of said two stations being able to communicate asynchronously while the other station being able to communicate synchronously and each station having a system unit coupled to a communications device, interconnected by a transmission network a device for incorporating in the one of said two stations communicating asynchronously so that said one of said two stations communicating asynchronously can communicate with the other station communicating synchronously, said device comprising: an interface means disposed between the system unit and the communications device said interface means receiving data arranged on byte boundaries from the system unit and passing said data asynchronously to the communications device; a first means for receiving a synchronous information frame from an application program being executed on the one of said two stations communicating asynchronously and for modifying said frame to allow transmission through the interface means; and a second means for receiving the frame from the interface means, searching the frame for sequences of predetermined bit patterns and substituting different sequences of bit patterns which makes the frame compatible for transmission, using a synchronous protocol, through the transmission network to the other station which communicates synchronously.

Claim 10

The device of claim 6 wherein the sequences of predetermined bit patterns include `7D5D` Hex, `7D5E` Hex, `7D31` Hex and `7D33` Hex.

Claim 11

The device of claim 7 wherein the different sequences of bit patterns in sequential order includes `7D` Hex, `7E` Hex, `11` Hex and `13` Hex.

Claim 12

The device of claim 4 or 5 wherein the COMM port includes a Universal Asynchronous Receiver/Transmitter (UART).

Claim 13

A communications system comprising: at least one computer having an asynchronous interface, a first means for receiving synchronous messages from an application program being executed on the at least one computer and processing the message by inserting characters to enable transmission through the asynchronous interface and an adapter having thereon a Universal Asynchronous Receiver/Transmitter (UART) for receiving the message from the asynchronous interface and a second means for receiving the message from the UART, removing selected ones of the characters inserted by the first means and inserting other characters to make said message compatible for transmission using a synchronous communications protocol; at least another computer having an adapter for receiving synchronous messages; and a transmission network for interconnecting the at least one computer and the at least other computer.

Claim 14

A communications system comprising: at least one computer having an asynchronous interface, a first means for receiving synchronous messages from an application program being executed on the at least one computer and processing the message by inserting characters to enable transmission through the asynchronous interface and an adapter having thereon a Universal Asynchronous Receiver/Transmitter (UART) for receiving the message from the asynchronous interface and a second means for receiving the message from the UART, removing selected ones of the characters inserted by the first means and inserting other characters to make said message compatible for transmission using a synchronous communications protocol; at least another computer having an adapter for receiving synchronous messages; and a transmission network for interconnecting the at least one computer and the at least other computer.

Claim 15

The communications system of claim 10 wherein the transmission network includes an Integrated Services Digital Network (ISDN).

Claim 16

A station for using in a communications network comprising a computer including an asynchronous interface, a first means for receiving synchronous messages from an application program being executed on the at least one computer and processing the message by inserting characters to enable transmission through the asynchronous interface and an adapter having thereon a Universal Asynchronous Receiver/Transmitter (UART) for receiving the message from the asynchronous interface and a second means for receiving the message from the UART removing selected ones of the characters inserted by the first means and inserting other characters to make said message compatible for transmission using a synchronous communications protocol.

Claim 17

A station for using in a communications network comprising a computer including an asynchronous interface, a first means for receiving synchronous messages from an application program being executed on the at least one computer and processing the message by inserting characters to enable transmission through the asynchronous interface and an adapter having thereon a Universal Asynchronous Receiver/Transmitter (UART) for receiving the message from the asynchronous interface and a second means for receiving the message from the UART removing selected ones of the characters inserted by the first means and inserting other characters to make said message compatible for transmission using a synchronous communications protocol.

Claim 18

The device of claim 6 wherein the sequences of predetermined bit patterns include `5E` Hex, `7E` Hex, `11` Hex and `13` Hex.

Claim 19

The device of claim 13 wherein the different sequences of bit patterns in sequential order includes `7D5D` Hex, `7D5E` Hex, `7D31` Hex and `7D33` Hex.

Claim 20

The device of claim 6 wherein the sequences of predetermined bit patterns include `DBDC` Hex and `DBDD` Hex.

Claim 21

The device of claim 15 wherein the different sequences of bit patterns in sequential order includes `CO` Hex and `DB` Hex.

Claim 22

The device of claim 6 wherein the sequences of predetermined bit patterns include `CO` Hex and `DB` Hex.

Claim 23

The device of claim 17 wherein the different sequences of bit patterns in sequential order includes `DBDC` Hex and `DBDD` Hex.

Claim 24

The device of claim 6 wherein the interface means includes a COMM port.