Wireless serial port transceiver

• US 7,126,935 B1
• Filed: 11/09/2000
• Issued: 10/24/2006
• Est. Priority Date: 10/09/1997
• Status: Expired due to Fees

• Current Assignee: Paxar Americas Incorporated (Avery Dennison Corporation)
• Original Assignee: Paxar Americas Incorporated (Avery Dennison Corporation)
• Inventors: Brown, John P., Morrison, Donald A., Tincher, Terry L.
• Primary Examiner(s): PHAM, BRENDA H
• Application Number:
  US09/710,351
• Time in Patent Office: 2,175 Days
• Field of Search: 370/389, 370/349, 370/475, 370/310, 370/313, 370/324, 370/401, 709/203, 709/202, 709/208, 709/209, 709/211, 709/230, 709/237, 710/1
• US Class Current: 370/349
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/0241 where no transmission is received, e.g. out of range of the transmitter
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A pair of compact, energy-efficient, intelligent, wireless transceiver units are designed to replace the cable that interconnects a portable bar-code scanner, keyboard, and display or other host to a portable bar-code printer or the like. When reset, the units exchange linkage packets and thereby exchange addresses. Thereafter, the two units communicate in an error-free fashion with each other, even in the presence of noise and interference, by exchanging addressed packets containing error detection information. Alternate transmission frequencies are selected when transmissions cannot be received at one frequency. The host unit may maintain independent linkages with multiple printers or the like, with a switch on the host unit selecting the desired printer. Power usage is minimized by shutting down transmitters, receivers, serial port drivers, and microprocessors whenever possible, and for extended periods when data is not being transmitted.

Claims

1. A data processing device that can establish and maintain a wireless communication link between itself and another nearby data processing device which shares the same communications protocol, said device comprising:

a radio transceiver;

memory within said device that can contain data to be transmitted;

said device operating in a master mode and being switchable between linkage and data communications modes;

said device, when in linkage mode, sending out inquiry signals seeking communication with another device that shares the same communications protocol but in slave mode;

said device exchanging addresses with another device that shares the same communications protocol but in slave mode and that responds to one of said inquiry signals and then switches into data communications mode;

said device thereafter retrieving from said memory any data that are to be transmitted, forming the data into error-correctable, addressed data packets, sending out the packets, and thereafter awaiting acknowledgment of successful receipt of such data, to transfer the data in an error free manner from it to another device that shares the same communications protocol.

2. A data processing device in accordance with claim 1 wherein the transceiver is designed to operate on at least two differing frequencies, with automatic provision for switching of communicating devices between frequencies, to minimize interference problems.

3. A data processing device in accordance with claim 1 wherein at least some transmitted packets are addressed using data derived from the address of at least one device.

4. A data processing device in accordance with claim 1 wherein said device, once having entered the data communications mode, sends out addressed send requests when no data are available to be transmitted, or packetized data when data are available to be transmitted.

5. A data processing device in accordance with claim 4 wherein at least the transceiver portions of said device enter a low-power state at times between the generation of said send requests and packetized data.

6. A data processing device in accordance with claim 4 wherein, after sending out send requests or packetized data, said device awaits the return transmission of either an acknowledgment of data correctly received or packetized return data, which return data are placed into said memory preparatory to being utilized by said device.

7. A data processing device in accordance with claim 1 wherein said data processing device includes a bar code reader.

8. A data processing device that can establish and maintain a wireless communication link between itself and another nearby data processing device which shares the same communications protocol, said device comprising:

a radio transceiver;

a memory within said device that can accept received incoming data;

said device operating in a slave mode and being switchable between linkage and data communications modes;

said device, when in linkage mode, listening for and responding to any received inquiries from another device in linkage mode and in master mode that shares the same communications protocol, said device exchanging addresses with said another device and then said device switches into data communications mode; and

said device thereafter, storing in said memory any data that are received in the form of error-correctable, addressed data packets that arrive, and thereafter acknowledging successful or unsuccessful receipt of such data packets, to receive the data in an error free manner from another device that shares the same communications protocol but that operates in master mode.

9. A data processing device in accordance with claim 8 wherein the transceiver is designed to operate on at least two differing frequencies, with automatic switching of communicating devices between frequencies to minimize interference problems.

10. A data processing device in accordance with claim 8 wherein at least some transmitted packets are identified by data derived from the address of at least one device.

11. A data processing device in accordance with claim 8 wherein at least the transceiver portions of said device enter a low-power state at times between the times of occurrence of said in coming data packets and periodiacally poser up to listen for incocming data packets.

12. A data processing device in accordance with claim 8 wherein said device, once having entered the data communications mode, listens for addressed send requests when no data are available to be transmitted from a master device, or for packetized data when data are available to be transmitted from a master device.

13. A data processing device in accordance with claim 11 wherein, after receiving a send request or a data packet, said device sends an acknowledgement of any data correctly received, or if its memory contains data to be sent out, an acknowledgment of data correctly received plus a packet of return data, which return data are retrieved from said memory preparatory to being transmitted.

14. A data processing device in accordance with claim 8 wherein said data processing device includes a printer.

15. A data processing device that can establish and maintain a wireless communication link between itself and another nearby data processing device which shares the same communications protocol, said device comprising:

a radio transceiver;

memory within said device that can contain data to be transmitted and that can accept received incoming data;

said device operating in a master mode and being switchable between linkage and data communications modes;

said device, when in linkage mode, sending out inquiry signals seeking communication with another device that shares the same communications protocol but in slave mode;

said device exchanging addresses with another device that shares the same communications protocol but in slave mode and that responds to one of said inquiry signals and then switches into data communications mode;

said device thereafter retrieving from said memory any data that are to be transmitted and transmitting said data in the form of packetized, error-correctable, addressed data packets, and thereafter awaiting acknowledgment of successful receipt of such data or awaiting acknowledgment plus a packet of return data, which return data are placed into said memory, to transfer data in an error free manner between it and another device that shares the same communications protocol but in slave mode.

16. A data processing device in accordance with claim 15 wherein the transceiver is designed to operate on at least two differing frequencies, with provision for automatic switching of communicating devices between frequencies, to minimize interference problems.

17. A data processing device in accordance with claim 15 wherein at least some transmitted packets are identified by data derived from the address of at least one device.

18. A data processing device in accordance with claim 15 wherein said device, once having entered the data communications mode, sends out addressed send requests when no data are available to be transmitted, thereafter listening for incoming data packets.

19. A data processing device in accordance with claim 18 wherein at least the transceiver portions of said device enter a low-power state at times between the generation of said send requests and when no data packets are being sent or received.

20. A data processing device in accordance with claim 15 wherein said data processing device includes a bar code reader.

21. A data processing device in accordance with claim 15 wherein said data processing device includes a printer.

22. A data processing device that can establish and maintain a wireless communication link between itself and another nearby data processing device which shares the same communications protocol, said device comprising:

a radio transceiver;

memory within said device that can contain data to be transmitted and accept received incoming data;

said device operating in a slave mode and being switchable between linkage and data communications modes;

said device, when in linkage mode, listening for and responding to any received inquiries from another device that shares the same communications protocol and that is in master mode, said device exchanging addresses with said another device and then switches into data communications mode; and

said device thereafter, in response to incoming data packets or send requests, accepts and places into said memory any data in said data packets and acknowledges receipt of any such data received and, if there are any data to transmit, retrieves from said memory the data that are to be transmitted and transmitting said data, where all such data are in the form of error-correctable, addressed data packets that are sent and acknowledged when successfully received, to transfer the data in an error free manner between it and another device that shares the same communications protocol but in master mode.

23. A data processing device in accordance with claim 22 wherein the transceiver is designed to operate on at least two differing frequencies, with provision for automatic switching of communicating devices between frequencies, to minimize interference problems.

24. A data processing device in accordance with claim 22 wherein at least some transmitted packets contain addresses derived from the address of at least one device.

25. A data processing device in accordance with claim 22 wherein at least the transceiver portions of said device enter a low-power state at times between the arrival of said incoming data packets and send requests when no data are to be transmitted or received, and periodically power up to listen for incoming data packets.

26. A data processing device in accordance with claim 22 wherein said data processing device includes a bar code reader.

27. A data processing device in accordance with claim 22 wherein said data processing device includes a printer.

28. A data processing device that can establish and maintain a wireless communication between itself and another nearby data processing device which shares the same communications protocol, said device comprising:

a radio transceiver;

a memory within said device that can contain data to be transmitted;

said device operating in a slave mode and being switchable between linkage and data communications modes;

said device, when in linkage mode, listening for and responding to any received inquiries from another device that shares the same communications protocol and that is in master mode, exchanging addresses with said another device and then switching into data communications mode; and

said device thereafter, in response to send requests, retrieves from said memory any data that are to be transmitted in the form of error-correctable, addressed data packets which are sent out following receipt of said send requests, and thereafter awaits acknowledgment of successful receipt of such data, to transfer the data in an error free manner between devices that share the same communications protocol.

29. A data processing device in accordance with claim 28 wherein the transceiver is designed to operate on at least two differing frequencies, with provision for automatic switching of communicating devices between frequencies to minimize interference problems.

30. A data processing device in accordance with claim 28 wherein at least some transmitted packets contain addresses derived from the address of at least one device.

31. A data processing device in accordance with claim 28 wherein said device, once having entered the data communications mode, can receive either send requests, when no incoming data have been sent, or packets of data, when incoming data are available and have been sent, and wherein said device stores said incoming data in said memory.

32. A data processing device in accordance with claim 31 wherein at least the transceiver portions of said device enter a low-power state at times between the receipt of incoming commands when no data are being transferred.

33. A data processing device in accordance with claim 28 wherein said data processing device includes a printer.

34. A data processing device that can establish and maintain a wireless communication link between itself and another nearby data processing device which shares the same communications protocol, said device comprising:

a radio transceiver;

memory within said device that can accept received incoming data;

said device operating in a master mode and being switchable between linkage and data communications modes;

said device, when in linkage mode, sending out inquiry signals seeking communication with another device that shares the same communications protocol but in slave mode;

said device exchanging addresses with another device that shares the same communications protocol and but in slave mode that responds to such inquiry signals and then switching into data communications mode;

said device thereafter sending out addressed periodic send requests and, in return, sometimes receiving back data in the form of error-correctable, addressed data packets that said device stores in said memory, said device acknowledging the successful receipt of such data, to transfer data in an error free manner from another device that shares the same communications protocol but in slave mode.

35. A data processing device in accordance with claim 34 wherein the transceiver is designed to operate on at least two differing frequencies, with provision for automatic switching of communicating devices between frequencies, to minimize interference problems.

36. A data processing device in accordance with claim 34 wherein at least some received packets contain addresses derived from the address of at least one device.

37. A data processing device in accordance with claim 34 wherein said device, once having entered the data communications mode, sends out addressed periodic send requests, when no data are available to be transmitted, or packets of data retrieved from said memory when data are available to be transmitted.

38. A data processing device in accordance with claim 34 wherein at least the transceiver portions of said device enter a low-power state at times between the generation of said periodic send requests, when no data are being transferred.

39. A data processing device in accordance with claim 34 wherein said data processing device includes a printer.

40. A data processing device that can establish and maintain a wireless communication link between itself and another nearby data processing device which shares the same communications protocol, said device comprising:

a radio transceiver;

memory within said device that can contain data to be transmitted and that can accept received incoming data;

said device capable of operating in either master or slave mode, and being switchable between linkage and data communications modes;

said device, when in linkage mode and master mode, sending out inquiry signals seeking communication with another device that shares the same communications protocol when in slave mode;

said device, when in linkage mode and slave mode, listening for and responding to any received inquiry signals from another device that shares the same communications protocol but in master mode;

said device, when in linkage and master mode, exchanges addresses with another device that shares the same communications protocol but in slave mode and that responds to such inquiry signals, and then switches into data communications mode;

said device, when in linkage and slave mode, exchanges addresses with another device that shares the same communications protocol but in master mode and from which the device receives an inquiry, and then switches into data communications mode; and

said device, when in master mode and data communications mode, sends out send requests or, when the memory contains data that are to be transmitted, retrieves from said memory such data that are to be transmitted and sends the data in the form of error-correctable, addressed data packets, and thereafter said device awaits acknowledgment of the successful receipt of any such data, or the receipt back of incoming error-correctable, addressed data packets; and

said device, when in slave mode and data communications mode, awaiting incoming error-correctable, addressed data packets or send requests and responds by accepting any data in said memory and sending out an acknowledgment of any incoming data and, if there is data to transmit, by sending out outgoing error-correctable, addressed data packets and awaiting acknowledgment.

41. A data processing device in accordance with claim 40 wherein the transceiver is designed to operate on at least two differing frequencies, with provision for automatic switching of communicating devices between frequencies, to minimize interference problems.

42. A data processing device in accordance with claim 40 wherein at least some transmitted packets contain addresses derived from the address of at least one device.

43. A data processing device in accordance with claim 40 wherein at least the transceiver portions of said device enter a low-power state at times between the generation and receipt of said send requests at times when no data are being transmitted or received.

44. A data processing device in accordance with claim 40 wherein said data processing device includes a bar code reader.

45. A data processing device in accordance with claim 40 wherein said data processing device includes a printer.

46. A method for conducting wireless communication between a source and sink for data comprising the steps of:

placing both said source and said sink into a first linkage mode;

defining one of said source and sink to be the master and defining the other to be the slave;

having the master send out inquiry signal pulses seeking a response from the slave;

having the slave, in response to receipt of such a signal pulse, send back a responsive signal pulse;

having the master and slave exchange addresses and thereafter both switch into a second data communications mode;

having the master send out send requests;

having the slave send out a signal responsive to at least some of said send requests;

having the source send data in place of at least some of its send requests, if it is the master, or with at least some of its responsive signals, if it is the slave;

having the sink receive data from any responsive signal containing data, if it is the master, or replacing any send requests, if it is the slave; and

formulating any data transmitted and received into error-correctable, addressed data packets, to thereby transfer data in an error-free manner.

47. A method in accordance with claim 46 which further includes provision for transmission of at least some data back from the sink to the source following the protocols described for transmission from the source to the sink.

48. A method in accordance with claim 46 wherein at least some the data transferred is descriptive of bar code information.

49. A method in accordance with claim 46 including the step of printing at least some of the information reaching the sink.

50. A unit, configurable as a master or slave, and installable in a data processing device, for enabling that device to communicate with another device containing a compatible device configured in the opposite master or slave state, said unit comprising:

a transceiver;

a control placing said device first into a linkage state to seek out a compatible unit and thereafter into a data communications state to communicate with a compatible unit once one is found;

a first mechanism within said unit when in said linkage state that sends out, if configured as a master, or that listens for and receives, if configured as a slave, inquiry signals, and that sends out, if configured as a slave, or receives, if configured as a master, an acknowledgment signal acknowledging receipt of any such inquiry signal that is successfully sent and received, and in either case, after interchanging inquiry and acknowledgment signals and exchanging addresses that places said unit into its data communications state;

a second mechanism within said unit when in said data communications state that causes said unit, if configured as a master, to send out send requests or data to be transmitted, or if configured as a slave, to acknowledge any data received by sending back an acknowledgment accompanied by any data to be transmitted, and in either case that accepts and acknowledges any incoming data, organizing said data sent or received into addressed, error-correctable data packets, to thereby transfer data in an error-free manner between said device and another device.

51. A unit in accordance with claim 50 wherein said unit powers itself down when no data are being transferred and no send requests are being sent or acknowledgment signals are expected.

52. A unit in accordance with claim 50 wherein said transceiver can operate on at least two different frequencies and wherein said unit, in its data communications state, can change frequencies in synchronism with another unit with which it communicates to minimize interference problems.

53. An apparatus for transferring data between a source of information and a sink for information by a wireless linkage comprising:

a first transceiver unit connecting to said source of information and having an address;

a second transceiver unit connecting to said sink for information and having an address;

a handshake protocol according to which the first and second transceiver units operate, which causes the transceiver units to continuously attempt to exchange addresses by one broadcasting its address and by the other responding with its own address;

said first and second transceiver units, following the successful exchange of addresses, placing themselves into a data communications mode where each communicates exclusively with the other and where said first and second units remain in said data communications mode indefinitely; and

said units thereafter wirelesslyy transferring data in the form of addressed data packets, and also transferring addressed acknowledgements of receipt of such data packets, to transfer data between said source and said sink.

54. A method for establishing a wireless linkage between a source and a sink for information comprising the steps of:

placing the source and the sink into a linkage mode where each is seeking out a linkage partner;

while both are in the linkage mode, causing the source and sink to continuously attempt to exchange addresses to link;

having said source and sink, following a successful link by address exchange, switch into a data communications mode where each communicates by address exclusively with the other and where said source and said sink then remain in said data communications mode indefinitely; and

while both are in the communications mode, having the source send addressed data packets to the sink, and having the sink return addressed acknowledgements of packet receipts.

55. A wireless link comprising:

first and second transceiver units each unit having a linkage mode and a data communications mode;

a handshake protocol within each unit placed into operation when the unit is in the linkage mode which enables one of a pair of such units to broadcast its address and which enables the other of the pair of such units to capture the broadcast address and to return its own address, the successful exchange of addresses causing the units to enter the data communication mode; and

a data exchange protocol within each pair of units for use in the data communication mode, which causes them to send packetized, addressed, error detectable data packets via radio to the other unit, receive such addressed packetized data, check the data for errors, and acknowledge an accurate transmission by sending a return-addressed acknowledgement packet to the other unit.

56. A wireless communication link for a device to allow the device to communicate with another device having an associated address comprising:

a transceiver having an associated address;

a handshake protocol according to which the transceiver operates to link to another device wherein the transceiver and other device exchange their addresses to become linked to one another; and

a data exchange protocol according to which the transceiver operates after becoming linked to the other device wherein the transceiver transmits an addressed data packet and receives an acknowledgement of receipt of the transmitted data packet or the transceiver receives an addressed data packet and transmits an acknowledgement of receipt of the received data packet.

57. A wireless communication link as recited in claim 56 wherein said transceiver is a modular unit connectable to a printer to allow the printer to communicate wirelessly with the other device.