Correlative Coding – Modified Duobinary Signaling
5 stars based on
This case is a continuation of application Ser. A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright modified duobinary signaling cascade has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserve all copyright rights whatsoever.
The present invention in a preferred implementation relates to improvements in radio data communication networks wherein a number of mobile transceiver units are to transmit data to a number of base stations under a wide range of operating conditions.
To compensate for the wide range of operating conditions, adaptability has been provided using an exchange of parameters that define the nature of the network communication. The invention is preferably to be applicable as an upgrade of an existing data capture system wherein a number of hand-held transceiver units of an earlier design are already in the field representing a substantial economic investment in comparison to the cost of base stations, accessories and components.
In installations spread over an extensive area, a large number of mobile portable transceiver units may be employed to gather data in various places and multiple base stations may be required. In a variety of such installations such as warehouse modified duobinary signaling cascade, distribution centers, and retail establishments, it may be advantageous to utilize not only multiple bases capable of communication with a single host, but with multiple hosts as well.
An early RF data collection system is shown in Marvin L. The exemplary prior art device is capable of communicating with a host computer through an RSC interface at up to 19, baud in asynchronous mode. In modified duobinary signaling cascade for an optional RS interface to be substituted for an RSC interface, the unit must be opened and substitute circuitry components installed within it.
The present invention provides an improved data communication system which maintains RF communication links between one or more host computers and one or more base transceiver units, each of which may be communicative with many mobile portable transceiver units being moved about a warehouse complex for the collection of data.
Specifically, the invention provides a data communication system for collecting and communicating data in the form of RF signals which has a plurality of RF transceivers that store and modify at least one variable operating parameter. From the stored parameter seach modified duobinary signaling cascade transceivers control the operation of transmission and reception.
The transceivers also evaluate the effect of the stored parameter based by analyzing each transmission received, and determine whether to modified duobinary signaling cascade changes in the stored parameter. If changes are needed, the transceivers, modify and store the modified operating parameter and begin operation based thereon.
The operating parameters involve: In addition, the RF transceivers used in the data communication network of the present invention use system-default values to reset the operating parameters if a series of failed communication exchanges occurs, so that communication can be reestablished. It is therefore an object of the invention to provide an adaptive radio communication system which permits the interconnection of one or two host computer devices to a multiplicity of base transceiver units which may modified duobinary signaling cascade both prior art existing installed units and new generation units capable of spread spectrum radio transmission.
It is a further object of the invention to provide an adaptive RF data communication system which optimizes communication based on a set of operating parameters. It is a further object of the invention modified duobinary signaling cascade provide an adaptive RF data communication system which maintains communication based on a set of operating parameters for optimizing communication, wherein the operating parameters involve: It is a further object of the invention to provide a radio communication system network controller which via a communication exchange optimizes a set of operating parameters, yet returns the parameters to their previous or system-default values upon modified duobinary signaling cascade communication.
These and other objects of the invention will be apparent from examination of the detailed modified duobinary signaling cascade which follows. By way of example, the base station may be comprised of a radio base unit 14 such as the model RB of Norand Corporation, Cedar Modified duobinary signaling cascade, Iowa, whgich forms part of modified duobinary signaling cascade product family known as the RT system.
In this case, the radio base 14 may receive data from the respective mobile RF terminals, modified duobinary signaling cascade. The data capture terminals 12A, 12B. Front panel 22 is provided with display 24 and select key 26, up key 28 and down key Power indicator 32 comprises a low power green light emitting diode which is energized when power is supplied to the invention Error condition indicator 34 is a yellow LED which is software controlled to be energized if the modified duobinary signaling cascade 10 is in error condition.
Invention network controller 40 is coupled to host computer 42 such that data may be interchanged between the devices over host communications link 44, which may be either in an RSC format modified duobinary signaling cascade selectively in an RS format.
The host communication link 44 couples to controller 40 at host port First communication port 48 of controller 40 provides means for coupling of network 50 to controller Network 50 comprises a number of base RF transceiver units 52A, 52B and 53B, each of which may be selectively employed in the radio frequency communication of data from mobile transceiver units.
It is to be understood that base transceiver units 52 are designed and equipped to be operable in the exchange of data with network controller 40 over network link 56 such that each base transceiver unit 52A, 52B, or 53C may independently exchange data with network controller 40 through first communication port When first communication port 48 is intended for operation with a network such as network 50 of base transceiver units 52A, 52B and 53C, for example, network controller 40 is selectively operated to provide an RS interface at first communication port The selection of interface to be provided at first communication port 48 is front panel controlled, that is, the user may operate front panel keys 28, 30 and 26 See FIG.
Base transceiver units 52A, 52B, and 52C are coupled to network link 56 by serial means, rather than parallel means, and each may be caused to modified duobinary signaling cascade or to receive independently from the others while additionally being communicative with network controller 40 in a randomly chosen fashion. It is further to be understood that interface translation is provided within controller 40 such that data communicated at first communication port 48 may be directed to host 42 at port 46 via properly chosen interface means as is required by the host 42 with which communication is intended.
Like first communication port 48, second communication port 57 may be internally switched among interface choices of these types: In the illustrated arrangement of FIG. Because of limitations of base transceiver 54, it must communicate via RSC interface format and therefore, second communication port 57 must be selected to operate in RSC interface mode.
However, when second communication port 57 is desired to communicate with a network via RS interface, front modified duobinary signaling cascade keys 26, 28 and 30 may be manipulated by the user to provide the RS interface availability at second communication port Likewise, second communication port 57 may be selected to operate as an RS interface, as a V. Diagnostic port 55 provides a fourth communication pathway for network controller 40, providing an asynchronous port operable at to 19, baud as an RSC interface.
When desirable, diagnostic port 55 may be coupled by diagnostic link 58 to diagnostic device 60 for purposes of error diagnosis of controller 40 by diagnostic device 60, or for reprogramming of memory devices within controller 40 when desired. It is contemplated that diagnostic device 60 comprises a 16 or 32 bit microprocessor commonly known as a personal computer or "PC". The mode of coupling between diagnostic device 60 and network controller 40 may be direct or through remote means by use of a modem.
Referring now to FIG. First data communication port 71 modified duobinary signaling cascade be selectively coupled to RS interface member 76 or V. The choice of whether RS interface member 76 or V.
The choice of whether first communication port 71 is coupled to interface member 76 or to interface member 78 depends on the modified duobinary signaling cascade panel selection made by the user by keys 26, 28, and 30 shown in FIG. By use of front panel keys 26, 28, and 30 of FIG. In the preferred embodiment of the invention 40, central processing unit 70 of FIG. Fourth communication port 74 of central processing unit is coupled to asynchronous RS interface member 97 to be available for interconnection of a diagnostic device therewith.
Also coupled to central processing unit 70 are display member 24 and keyboard member 31 with which keys 26, 28, and 30 of front panel 22 FIG. Power supply member is selectively attachable to invention network controller In order to avoid the necessity of different models of network controller 40 depending on the local electrical power utility's operating characteristics, power supply is provided in optional models depending on the country in which it is to be used, power supply being capable of providing satisfactory output power to network controller 40 modified duobinary signaling cascade of the voltage or frequency of the input source provided to power supply Central processing unit interface is coupled to asynchronous signal processing element by signal path Asynchronous signal processing element comprises a baud rate generator cooperative with a universal asynchronous receiver-transmitter.
Also coupled to central processing unit interface is network clock and control member which comprises a programmable network clock generator which can be selectively programmed to generate an optional clock speed for a network to be coupled through RS interfaces 82 and 90 seen in FIG.
Network clock and control member also provides detection means modified duobinary signaling cascade detections of failure conditions on a linked network and provides control signals to system components in response thereto, including interrupt signals to programmable interrupt coordinator circuitry included in central processing interface Network clock and controller member provides data encoding by the FMO standard, then the encoded data modified duobinary signaling cascade be operated upon by RS interfaces 82 and 84 and transmitted and received by single twisted pair means to multiple serially networked base transceiver units exemplified by base transceiver unit 52A, 52B, and 52C illustrated in FIG.
Central processing unit interface is also coupled by line to latches exterior to ASIC The bar code data received by said base transceiver units is then transmitted in the example of FIG. It will be observed that the components correspond with components of the network controller of FIG.
Thus, the significance of components through,and will be apparent modified duobinary signaling cascade the preceding description with respect to FIG. Port 74 is coupled with a modem providing for remote diagnostics and reprogramming of the network controller Port 73 of modified duobinary signaling cascade controller 40 is shown as being connected with an adapter modified duobinary signaling cascade known as modified duobinary signaling cascade MBA In the operating mode indicated in FIG.
Component is a commercially available radio base known as the RB which utilizes features of Sojka U. Base station may communicate with a multiplicity of hand-held RF data terminals such as indicated at Base is indicated as being coupled with the adaptor via RF broadband modems and Base units and may communicate with a variety of mobile transceiver units such as those indicated at and In this example, the second ports 72 of the controllers 40A and 40B are configured for communication a relatively high data rate relatively along a distance network channel 56 which may have the characteristics of the serial channel 56 of FIG.
Furthermore, the network transceivers may have RF coupling with router transceiver units such as indicated atand Router transceiver unit is illustrated as a RB intelligent transceiver such as represented in FIG. Suitable interfaces are indicated at and modified duobinary signaling cascade Suitable interface means are indicated at and Host A is shown with a printer or other peripheral P1 which may generate bar codes, for example, for replacement of damaged bar codes or the like.
Another printer P2 is shown associated with base 52C, again for example, for producing bar code labels where those are needed in the vicinity of a base station. In a large warehouse, relatively large distances may be involved for a worker to return to a printer such as P1 to obtain a new bar code label. Thus, it may be very advantageous to provide a printer P2 at the base station 52C which may be relatively close to a processing location which requires printed labels, e.
A base 52F may have a peripheral P3 associated therewith such as a large screen display, a printer or the like which may supplement the capabilities of a hand-held terminal, for example printing out new bar code labels at a convenient location, or providing a full screen display, rather than the more limited screen display area of the hand-held terminal If, for example, a base radio 52D which might be located at the ceiling level of a warehouse became inoperative at a time when qualified repair personnel were not immediately available, with the present system it would be feasible to provide a substitute base radio or base radios, for example, as indicated at 52D1 located at table level or the like.
With the present system, the base radio stations do not modified duobinary signaling cascade forward data communications received from a given terminal to a particular host.
For example, hand-held terminal may request a path to printer P2, and such a path may be created via base stations 52D1 and 52C.
Station 52C upon receipt of the message form terminal would not transmit the message to a host but would, for example, produce the desired bar code label by means of printer P2. Further, terminal may have provision for digitizing a voice message which might, for example, be addressed to terminal The system as illustrated would be operable to automatically establish a suitable path for example, via stations 52D1, 52C, 52B, 52E and for the transmission modified duobinary signaling cascade this voice message in digital form.
Successive segments of such a voice message would be stored, for example, by the terminaland when the complete message was assembled, the segments would be synthesized into a continuous voice message for the user of terminal e. In accordance with the present invention, a hardware system such as illustrated in FIG. For example, controller 40B could successively try its communications options with its output ports such asdetermining for example, that host processors were coupled with ports 71 and 72, one operating on a The controller 40B having thus automatically configured itself so as to be compatible with the devices connected to ports 71 and 72, could proceed to transmit via port 73 a suitable inquiry message to the network channel Although a polling protocol is preferred, each of the base stations could operate, for example, on a carrier-sense multiple-access CSMA basis or using a busy tone protocol to respond to the inquiry message from the controller 40B, until each of the successive bases on the network had responded and identified itself.
Each base, for example, would have a respective unique address identification which modified duobinary signaling cascade could transmit in response to the inquiry message so as to establish its presence on the modified duobinary signaling cascade.
The controller 40B could then transmit auto configure commands to the successive bases in turn, instructing the bases to determine what peripherals and router bases such as 52D1, 52E and 52F were within the range of such base, and to report back to the controller.
For example, bases such as 52C and 52F could determine the nature of peripherals P2 and P3 associated therewith so as to be able to respond to an inquiry form a terminal such as to advise the terminal that a bar code printer, for example, was within direct RF range. In the case of a breakdown of a component of the system such as 52D, it would merely be necessary to place a router device such as 52D1 at a convenient location and activate the unit, whereupon the unit could send out its own broadcast inquiry which, for example, could be answered by the base stations 52C and 52F, station 52C in turn, advising a relevant host or hosts of the activation of a substitute router station.
Thus, the system is conveniently re-self-configured without the necessity for a technician familiar with the particular configuration procedure.