Communicating system.

0001This invention relates to a system including a plurality of stations disposed in a logical sequence for providing a communication of data between different stations in the sequence on a cyclic basis. The invention also relates to a system including a plurality of stations which are interconnected to form a local area and/or wide area networking system for providing a communication of data from each station in the system to other stations in the system. The system of this invention is particularly adapted to logically splice stations into and out of a sequence without affecting the operation of other stations in the sequence. This invention also relates to a method of providing a controlled communication of data between different stations in a sequence.

0002Systems for recording and controlling the creation of music have become increasingly complex and sophisticated with the advent and development of digital computers and data processing systems. For example, a musical product can be shaped by the use of systems including digital computers and data processing to provide sounds and effects not capable of being provided from the capabilities normally provided by any instrument or combination of instruments.

0003Even though the systems now in use can provide sounds and effects not capable of being normally provided by any instrument or combination of instruments, such systems have severe limitations in their use. For example, the systems now in use transmit data from different stations in the system at a relatively low rate such as approximately 31.25 kilobits per second. This limits the number of stations which can be included in the system before undesirable audible effects occur. For example, when ten (10) stations are included in such a system, the delay between the communication of information from the first and last stations is audible to the ear. When as many as twenty (20) stations are included in the system, the delay between communications from the first and last stations is objectionable. This can be overcome somewhat by providing parallel networks but it is not easy to construct or control such configurations.

0004The systems now in use enable a plurality of music synthesizers from different manufacturers to be controlled from a single source at the same time. However, the systems do not have the flexibility of providing for the insertion of new stations into the sequence or of providing for the removal of stations from the sequence without affecting at least temporarily the sound produced by such systems. Because of this, the systems now in use do not have the flexibility which performers often desire and even require. For example, they prevent different synthesizers and master keyboards from being included in the system on a flexible basis.

0005The systems now in use also lack other flexibilities. For example, during the time that a system is being set up, different stations in the set-up mode may transmit data packets to other stations in the set-up mode. In this way, adjustments can be provided in the sound and sound effects transmitted by the different stations to provide a balance in the composite sound from the different stations. After this adjustment has been provided, it may be desired to provide for an operation of the stations in a performance mode where the performers at different stations actually perform in producing music which is melded into a composite sound. It may be desired to have not all of the stations in the set-up mode included in the performance mode.

0006The systems now in use are not able to be converted easily from the set-up mode to the performance mode, particularly when only selected stations in the set-up mode operate in the performance mode. For example, the systems now in use often require changes in the connections between different stations to be made physically under such circumstances so that an interruption in the operation of the system occurs.

0007The limitations discussed in the previous paragraph have been compounded or aggravated because the instruments, such as synthesizers, at the different stations have been manufactured by different companies and have been provided with different data bases by such different manufacturers. This has required different programs to be used for the different stations. Even with the expanded capabilities of current data processing systems, it has been difficult for the data processing systems to meld the different programs into an operative system.

0008There are other serious problems with the systems now in use. For example, several stations may inadvertently become simultaneously disconnected from the system. Under such circumstances, it has been difficult for the systems now in use to adapt quickly to restore such stations into the system. As another example, when the power to the systems now in use has been turned on, it has been difficult for the stations to become programmed into the system automatically and quickly in a particular sequence.

0009This invention provides a system which overcomes all of the limitations discussed in the previous paragraph. The system of this invention is able quickly to splice stations into a sequence or splice stations out of the sequence in accordance with communications from such stations without affecting the operation of other stations in the sequence. It is also able to splice stations quickly out of a sequence without affecting the operation of other stations in the sequence when attempts to communicate with such spliced- out stations are unsuccessful. It is able to change between a set-up mode and a performance mode in accordance with communications from such stations which will be operating in the performance mode. It is also able to return at any time to the set-up mode. It is able to restore stations into the system, without affecting the operation of other stations in the sequence and without any noticeable interruption in the operation of the system, when such stations are inadvertently lost from the system. It is further able to connect the stations quickly in a proper sequence in the system when power is first applied to the system in a start-up mode.

0010In one embodiment of the invention, stations accepting a vector from preceding stations in the sequence communicate data packets to other stations in the sequence. Each station receiving the vector can become spliced out of the sequence by communicating such a desire to the preceding station in the sequence. The communicating station then provides for the passing of the vector to the station following the next station in the sequence.

0011Alternatively, an individual station (not in the sequence) between the communicating and next stations can communicate to all stations, before any response from the next station, its desire to be spliced into the sequence. This station then splices into the sequence. If the next station does not respond to the station communicating with it, the communicating station can splice the next station out of the sequence and provide for the passing of the vector to the station following the next station in the sequence.

0012When stations in the sequence are in a set-up mode, only some stations may be in a performance mode higher than the set-up mode. Any station programmed to be active in the sequence and to operate in the performance mode may initiate an operation in the performance mode sequence when the stations are in the set-up mode. In each cycle of operation in the performance mode, if no station in the performance mode requests the operation to continue in the performance mode, the stations will revert to the set-up mode.

0013If several successive stations become lost from the sequence, the sequence becomes patched by a special communication from the station preceding such successive stations to include the next one of these successive stations in the sequence. This station then patches itself into the sequence. This process continues until all of the stations have been patched into the sequence. In a start-up operation, a first station identifies itself, and by communication to the other stations the special communication then occurs in the sequence described above in this paragraph to progressively patch such other stations into the sequence.

0014In the drawings: <ul id="ul0001" list-style="none"><li>Figure 1 illustrates the format of signals communicated between different stations in a sequence defining one embodiment of this invention;</li><li>Figure 1 A is a table indicating different types of information represented by the format shown in Figure 1;</li><li>Figure 2 illustrates the time sequence for the transmission of the signals in the format shown in Figure 1;</li><li>Figure 2A indicates different registers included at each station in the sequence to provide for the proper operation of such station in the sequence;</li><li>Figure 3 illustrates a first sequence of stations in a set-up mode and another sequence of stations in a performance mode, the performance mode being at a higher level than the set-up mode, and further illustrates how a vector is passed to successive stations in each of the sequences respectively constituting the set-up mode and the performance mode;</li><li>Figure 4 illustrates the relationship of the stations shown in Figure 3 when an additional station not in a sequence is to be spliced into the sequence and the relationship of the stations after the additional station has been spliced into the sequence;</li><li>Figure 4A illustrates an example of the sequence of events for splicing into the sequence the additional station shown in Figure 4;</li><li>Figure 5 illustrates the relationship of the stations shown in Figure 3 when one of the stations in the sequence is to be spliced out of the sequence and further illustrates the relationship of the stations when such station has been spliced out of the sequence;</li><li>Figure 5A illustrates an example of the sequence of events for splicing out of the sequence the station shown in Figure 5;</li><li>Figure 6 figuratively illustrates the interrelationship between the stations in the set-up mode and the stations in the performance mode, the performance mode being at a higher level than the set-up mode;</li><li>Figure 7 provides a schematic illustration of the interrelationship between the stations in a set-up mode and the stations in a performance mode when the stations are changed from an operation in the set-up mode to an operation in the performance mode;</li><li>Figure 8 illustrates the relationship between a plurality of stations in a sequence and further illustrates the interrelationship established between such stations when one of the stations is lost from the sequence;</li><li>Figure 9 illustrates the relationship between a plurality of stations in a sequence and further illustrates the interrelationship established between such stations when more than one of the stations is lost from the sequence; and</li><li>Figures 10A-10F provide specific examples on a timed basis of different types of operations shown in Figures 3-9.</li></ul>

0015This invention includes a plurality of stations displaced from one another and operative to become activated in a logical sequence. For example, in the embodiment shown in Figure 3, a plurality of stations designated as 8, 9, 10, 11, 12, n-1 and n are displaced from one another and are operative to become activated in a sequence. As one example, different musical instruments may be disposed at individual ones of the stations in the sequence. Alternatively, musical equipment may be disposed at certain stations in the sequence and control equipment such as equipment for receiving data to provide for a blending and shaping of the sounds from the different instruments may be disposed at other stations in the sequence. However, it will be appreciated that the disposition of musical instruments and controls at the individual stations in the sequence is only by way of illustration and that other types of equipment may be disposed at the stations in the sequence for purposes far removed from the blending and shaping of musical sounds.

0016Alternatively, the same type of equipment may be disposed at the individual stations in the sequence but different types of messages may be transmitted from such equipment at the individual stations in the sequence to other stations in the sequence. These types of messages may constitute measurements of parameters such as temperature, pressure and humidity. These measurements may be transmitted from each station in the sequence to other stations in the sequence to control the operation of equipment at such other stations or may be transmitted to a centralized data processing station which then processes such signals and communicates with the stations to indicate how such stations should operate.

0017In the normal mode of operation, the stations in the sequence become successively activated. For example, station 8 in Figure 3 may be initially activated by the passage of a vector to station 8. When activated, station 8 may communicate a data packet to another station, such as station 12, in the sequence. Such a communication will be discussed in detail subsequently. The data packet communicated from station 8 to station 12 may include data representing sounds from a musical instrument, or from musical instruments, at station 8. Alternatively, the data packet communicated from station 8 to station 12 may be an instruction to station 12 to emphasize sound in a certain frequency range or to mute sound in another frequency range.

0018It will be appreciated that data representing sounds are only one of a myriad of different communications which may be provided by the station 8 and the other stations in the sequence. For example, although the invention is specifically disclosed with reference to musical equipments and musical systems, it will be appreciated that the invention is intended to receive and communicate data, preferably in digital form, relating to any parameters, equipments and systems.

0019After station 8 has communicated the data packet to station 12, station 8 communicates in Figure 3 a packet to the other stations to activate a particular one of the stations in the sequence. For example, station 9 may be the next station in the sequence. Although the activating packet may be communicated to all of the stations in the sequence, it may be specifically directed in its coding to the station to be activated. To distinguish between the communication of a data packet and the communication of a packet for activating a station (e.g. station 9), the communication of the activating packet to all of the stations, but intended for a particular station, is designated as "providing for the passing of a vector". The passing of the vector from station 8 to all of the stations occurs through the transmission of information from station 8 in a form which station 9 can identify as the passing of the vector to station 9 by specific information in such transmission.

0020When station 9 receives the vector from station 8, station 9 transmits a data packet to another station such as station n. This indicates to station 8 that station 9 has received and accepted the vector. Station 9 then provides for the passing of the vector to station 10 by communicating the vector to all of the stations in the sequence. However, the vector is specifically directed in its coding to station 10, the next station in the sequence shown in Figure 3. In this way, each station in the sequence progressively receives the vector and transmits a data packet to another station, or other stations, in the sequence.

0021This invention is able to accomplish results not capable of being accomplished in the prior art. For example, as shown by double lines in Figure 4, a sequence may constitute stations 8, 10 and n-1. When the vector has passed to station 10 and station 10 has transmitted a data packet to another station, station 10 then provides for the passage of the vector to station n-1 by communicating the vector to all of the stations but specifying station in the coding in such communication. However, before station n-1 can accept the vector from station 10, station 11 can intervene and send a data packet to another station. Station 11 is able to intervene at this time because it is disposed between stations 10 and n-1. Station 11 then provides for the passing of the vector to station n-1 for the transmission of a data packet from station n-1.

0022Station 11 is thereafter spliced into the sequence so that the sequence includes stations 8, 10, 11 and n-1. In such a sequence, station 11 receives the vector from station 10 in each cycle of operation and provides for the passing of the vector to station n-1. This is indicated by broken lines between stations 10 and 11 and between stations 11 and n-1 and by double lines between stations n-1 and 8 and between stations 8 and 10.

0023The sequences discussed above and other sequences will be discussed in detail subsequently. For example, in Figure 5, station 10 may be spliced out of a sequence originally constituting stations 8, 10, 12 and n (as indicated by double lines joining the stations) and subsequently constituting stations 8, 12 and n. In the sequence shown in Figure 5, station 10 is spliced out of the sequence specifically on the basis of instructions from such station.

0024Figure 1 indicates the different types of packets communicated between stations in a sequence. Each packet is in a particular format. For example, each packet initially may include a "Preamble". The preamble may be in a form to synchronize the transmission of information by one (1) station with the reception, acknowledgement and decoding of such information by another station. For example, each preamble may consist of sixteen (16) successive binary bits each having a logic level designating a binary "1".

0025Following the preamble in each packet in Figure 1 is a "Flag". The flag may consist of a plurality of binary bits in a particular pattern. For example, the flag may consist of six (6) successive binary bits each having a logic level designating a binary "1". The flag may identify that the transmission of pertinent information in each packet follows the flag.

0026After the generation of the flag, each packet may include an "Address" designating the station or stations to which the packet is being sent. For example, different stations are identified in Figure 1 as "FFnn", "FEoo", "FDnn", "FBnn", "FCnn", "FFFF" and "gggg". The designation "gggg" indicates that the data packet is to be transmitted by the communicating station to all of the other stations in the sequence. The address in each data packet may be in the form of a plurality of binary bits in a hexadecimal code. This format constitutes a world-wide standard well known in the art.

0027Packets with an "Address" of "FFFF" are to be received and processed by all of the stations in the sequence. An Address of "FFFF" is used for such functions as system timing information and sequencer controls. An Address flag of "FFnn" is used to implement the protocol of providing for the passing the vector. An Address of "FEnn" indicates the transmission of a packet to a particular station, which then acknowledges the receipt of the packet by sending a response packet to this effect to the communicating station. The Address "FDnn" represents the response packet which the receiving station sends to the communicating station to acknowledge that it has received the packet from the communicating station. An Address of "FCnn" is actually not being used at present but is being reserved for future applications. In each of the different Address, different designations between "oo" and "nn" are used to identify individual stations in the sequence.

0028As indicated in Figure 1, the station providing the communicating packet may next identify itself in a plurality of bits designated as "Source station ID". This identification is stored in a register identified as "MID" (meaning "My Identification") in Figure 2A. In Figure 1, each of the different examples is identified as being transmitted by a single source. This source is identified in Figure 1 as "ss". It will be appreciated that different designations may be provided for the individual stations in the portion of each packet identified as "Source Station ID".

0029Particular information identified as "Packet Type" in Figure 1 is then transmitted in each packet to indicate the type of packet being communicated. For example, the particular information may indicate that the communicating station desires to be spliced into the sequence or that it desires to be spliced out of the sequence. The particular information identified as "Packet Type" may also indicate the speed of response of the communicating station. This is indicated by the designation "pd" in Figure 1. Each station in the sequence may have an individual speed of response and this speed of response may be different from the speed of response of the other stations in the sequence. The system then adjusts its speed of response automatically to the station having the lowest speed of response in the sequence.

0030The particular information identified as "Packet Type" in each packet may also provide a wide variety of other indications. These are numbered in Figure 1 as "0"-"225" in the column under the portion of the communication identified as "Packet Type". For example, the numeral "4" may designate the operation of a tape transport. As another example, the numeral "2" may designate "MIDI" (events, real-time, system, SYSEX). The term "MIDI" refers to a system now in widespread use for providing a digital control on a remote basis over the operation of musical synthesizers. Such a system does not have a number of the features disclosed and claimed for the system of this invention.

0031The "Packet Type" may also identify in coded form a "Real Time Vector" ("RTV") indicated in Figures 1 and 1A. The Real Time Vector indicates that information such as numerical information is being transmitted in the following portion (designated as " Packet Data") in each packet. This Real Time Vector may be further defined in the "Packet Data" (the portion of the packet following the "Packet Type") by a zero (0), a one (1) or a number of data bytes. The data bytes are identified schematically in Figure 1 as "ddd...ddd" to indicate that the number of data bytes is variable for each packet communicated from a station in the sequence to one or more of the other stations in the sequence. The letter "d" symbolically indicates that any value can be provided in the sequence designated as "ddd...ddd".

0032After the vector has been passed from a station in the sequence to the next station in the sequence, (e.g. from station 8 to station 9 in Figure 3), the station (e.g. station 9) receiving the vector communicates certain information in the portion of each communication designated as "Packet Data". This portion of the communication follows the portion of the communication identified as "Packet Type" information in the "Packet Data". For example, it provides information designated as "pmi" in Figures 1 and 1A. This identifies whether the station (e.g. station 9) receiving the vector will be one of the active stations in the sequence at level "pmi", when the level "pmi" should become active. It also identifies, as by the designation "pma" in Figures 1 and 1A, the mode (or hierarchy) of the ring in which the different stations are currently operating. For example, as shown in Figure 6, a set-up mode may be used while the sounds from the instruments at the different stations are being blended and shaped by the data transmitted between stations. A performance mode may be used after the sounds of the instruments at the different stations have been blended and shaped and the performance is about to begin. Generally, the number of stations in the performance mode is less than the number of stations in the set-up mode. The "pma" code identifies the particular mode in which the station (e.g. station 9) passing the vector is operating.

0033It will be appreciated that the "pmi" and "pma" codes appear in the "Data Packet" when one station communicates a vector to all of the other stations but identifies in the vector packet that a particular one of the stations is to receive the vector. It will also be appreciated that there may be more than two (2) modes without departing from the scope of the invention. For example, sixteen (16) different modes may be provided through the use of four (4) binary bits having individual patterns of operation to represent the different modes. It will be further appreciated that a transition can be made from any of the modes to any other one of the modes by selecting individual patterns for the four (4) binary bits.

0034After the communication of the "Packet Data", a plurality of bits are generated in each packet. These bits are indicated in Figure 1 by the portion of the packet designated as "Cycle Redundency Sum" and are illustratively identified in Figure 1 as "cccc". These bits are used to check the bits previously generated in each packet and indicate from such check whether all of the bits required to be generated in each of the previous portions of the packet have been properly generated. A cycle redundency verify to check the proper generation of the previous bits is well known in the art.

0035Each packet includes a flag at the end of the packet. This flag may include a plurality of bits in a particular format. This format may illustratively constitute a sequence of six (6) binary 1's. The flag at the end of the packet indicates that the generation of the packet has been completed. To separate the generation of successive packets,

0036an idle period is imposed after each such generation. This idle period insures that the generation and processing of information in each packet will be separate from the generation and processing of information in other packets so that there will be no interference or conglomeration between the information in different packets. This idle period may be represented by the generation of a plurality of bits in a particular format. For example, the idle period may be represented by the generation of sixteen (16) successive binary 1's.

0037Figure 2 indicates the generation of successive packets and the significance of such successive generations. As previously indicated, each packet is generated at a particular rate controlled by the station in the sequence with the slowest response time. The particular rate may also be dependent upon the length of the lines between the different stations in the sequence. This delay time may be quite long since one station in a sequence may illustratively be in Los Angeles and another station in the sequence may illustratively be in Kansas City. The time for the generation of each packet is designated as the "process delay time" and is identified as "pd" in such drawings as Figures 1, 1A and 2. The process delay time for the generation of each packet may illustratively be one hundred microseconds (100 sec.).

0038As shown in Figure 2, a station (e.g. station 8) may initiate the generation of a packet to another station (e.g. station 9) at zero process delay time (o pd). This packet may constitute the generation of data or the generation of a vector which may be broadly considered as one form of data. station 9 does not acknowledge the receipt of this packet until after a particular period of time such as one process delay time (1 pd). This acknowledgement is provided by the communication of a data packet by station 9 to another station, a group of stations or all of the stations in the sequence. This is indicated in Figure 2 by the designation "Vector/Data". This represents a period of two process delay time (2 pd) after station 8 has completed the transmission of the packet to station 9. The data packet may also constitute the transmission of a vector if station 9 does not have to, or does not wish to, transmit data to another station.

0039Each station identifies in a register the next station in a sequence. This register is identified in Figure 2A as "NID" (meaning "Next Identification"). Furthermore, each station receiving a vector identifies the station passing the vector. This identification is made in a register identified in Figure 2A as "PID" (meaning "Previous Identification"). Each station also has a register identified in Figure 2A as "PNID". This indicates the next station in the sequence with an operation in the performance mode.

0040Figure 3 indicates a plurality of stations in a set-up mode. These stations illustratively include stations 8, 9, 10, 11, 12, n-1 and n. The stations are in the set-up mode to make certain that the stations are all operating properly. The stations are also often in the set-up mode to provide for a processing of the data, such as data representing sounds from the different stations to blend and shape such sounds.

0041It will be appreciated that each station (e.g. station 8) in the set-up mode provides for the passing of the vector to the next station (e.g. station 9) in the set-up mode in Figure 3. The provision for the passing of the vector is indicated at "FF" in the address in Figure 1 and the station receiving the vector is generally identified by the designation "nn" following the code "FF" for the provision of the passaging of the vector.

0042After receiving the vector, each station in Figure 3 is also able to transmit a "data packet" to any other individual station in the sequence. The address portion of the data packet in Figure 1 indicates the station or station receiving such data packet. The designation "nn" following the designation "FE" in Figure 1 indicates on a general basis the particular station to which the data packet is being communicated. Alternatively, each station receiving the vector is able to communicate a data packet to a selective group of stations in the sequence. For example, station 8 may communicate a data packet to all of the stations where a guitar is located. This is indicated at "gggg" in Figure 1. As a further alternative, each station may communicate a data packet to all of the other stations in the sequence. This is indicated at "FFFF" in Figure 1. This is designated as a "broadcast" mode.

0043When a station (e.g. station 12) individually receives a data packet from a communicating station (e.g. station 8), it responds after a particular period such as one process delay time (1 pd). This response from station 12 acknowledges to station 8 that it has received the data packet. The acknowledgement of the receipt of a data packet by a receiving station (e.g. station 12) to a communicating station (e.g. station 8) is indicated in Figure 1 by a designation such as "FD" in the address portion of the packet transmitted by station 12 to station 8. This is followed in the Address by bits (generally designated as nn in Figure 1) identifying the station 8.

0044An example of the acknowledgement of a communication of a data packet is also indicated in Figure 10A. In Figure 10A, a vector passes from station 15 to station 1. After a delay of two process delay times (2 pd), station 1 communicates a data packet individually to station 7. After an additional delay of two process delay times (2 pd), station 7 acknowledges to station 1 that it has received the data packet from station 1. Two process delay times (2 pd) later, station 1 provides for the passing of the vector to station 2.

0045Figure 10B illustrates the multicast of a data packet from a station to a specialized group of stations designated as stations gggg and the time sequence involved in such a broadcast. In Figure 10B, a vector passes from station 4 to station 5. After a delay of two process delay times (2 pd), station 5 communicates a data packet to the stations in the selected group gggg. As previously described, the selected group may be illustratively be those stations having a guitar located at the stations. Since a group of stations is involved and particularly since the group may be large, the stations in the group gggg do not acknowledge to station 5 that they have received the data packet from station 5. Instead, after an additional period such as one process delay time (1 pd), station 5 provides for the passing of the vector to station 6.

0046As previously indicated, a communicating station may sometimes broadcast a data packet to all of the other stations in a sequence. Under such circumstances, the stations receiving the vector do not communicate to the communicating station that they have received the data packet. Instead, after an additional delay period such as one process delay time (1 pd), the communicating station provides for the passage of the vector to the next station in the sequence.

0047Figure 3 indicates a group of stations 8, 9, 10, 11, 12, n-1 and n operative in a set-up mode. This is indicated in Figure 3 by solid lines extending between successive pairs of stations in the sequence constituting the set-up mode. Figure 3 also indicates a group of stations operative in the performance mode. Since the performance mode is generally at a higher level than the set-up mode, not all of the stations in the set-up mode are included in the performance mode. The stations in the performance mode in Figure 3 constitute stations 8, 10 and n-1. The stations in the performance mode are indicated in Figure 3 by broken lines extending between the stations. As described previously and will be as described in detail subsequently, operations may be provided in the set-up mode and in the performance mode at different times.

0048Figure 4 also illustrates, by single lines between stations, the stations operating in the set-up mode and further illustrates, by double lines, the stations operating in the performance mode. Assume for the subsequent discussion in this paragraph and the following paragraphs that the stations in Figure 4 are operating in the performance mode. These stations constitute stations 8, 10 and n-1. When the vector has passed to station 10 and station 10 has communicated a data packet to one or both of the other stations in the performance mode, station 10 then provides for the passing of the vector to station n-1. Station n-1 would normally communicate a data packet to another station, as other stations, in the sequence after two process delay times (2 pd) discussed above (and as shown in Figure 2 by the indication "vector/data" at 2 pd). However, after one process delay time (1 pd), any station between station 10 and station n-1 has the right to send a data packet that it wishes to be spliced into the sequence. This time splice is indicated in Figure 2 by the word "splice" adjacent the time delay indicated at one process delay time (1 pd). The splicing station directs a splice packet to station 10 to cause station 10 to modify its next identification (NID) station information to specify such splicing station.

0049In the example shown in Figures 4 and 4A, station 11 provides a communication after one process delay time (1 pd) that it wishes to be spliced into the sequence. Furthermore, in the example shown in Figure 4A, station 11 communicates a data packet to a special group of stations, such as stations "gggg", with individual characteristics common to the group. Station 11 then provides for the passing of the vector to station n-1. Thereafter station 11 is included in the performance mode. As a result, station 10 thereafter provides for the passing of the vector to station 11 and station 11 provides for the passing of the vector to station n-1. This is indicated in Figure 4 by a broken line extending between stations 10 and 11 and by another broken line extending between stations 11 and n-1.

0050Figure 10C illustrates another example of a splice-in transaction and further illustrates the time sequence for this transaction. In the splice-in transaction of Figure 10C, station 9 provides for the passing of the vector to station 12. After one process delay time (1 pd), station 11 sends a data packet to a special group of stations gggg having common characteristics different from the other stations in the sequence. This data packet consists of a Real Time Vector of n data bytes designated as "ddd...ddd". After two (2) additional process delay times (2 pd), station 11 provides for the passing of the vector to station 12. Station 11 is thereafter spliced into the station. Station 11 accordingly receives the vector from station 8 and station 12 subsequently receives the vector from station 11.

0051Figures 5 and 5A illustrate an example where a station is spliced out of a sequence by a voluntary and positive action of that station. In the example shown in Figure 5, stations 8, 9, 10, 11, 12, n-1, n and 20 are shown by single lines between pairs of successive stations as constituting a sequence in the set-up mode. Stations 8, 10, 12 and n are shown by double lines in Figure 5 as constituting a sequence in the performance mode. The line between stations 10 and 12 in this sequence is shown in broken lines since station 12 is to be voluntarily and positively spliced out of the system. For the purposes of the example in Figures 5 and 5A, assume that the stations are in the performance mode, that the vector has passed to station 8 and that station 8 provides for the passing of the vector to station 10. Assume also that station 10 does not wish to be included any longer in the sequence constituting the performance mode.

0052When station 10 receives the vector in the example shown in Figures 5 and 5A, it sends a data packet back to that it no longer wishes to be included in the performance mode sequence. This data packet further indicates that station 8 should subsequently provide for the passing of the vector to station 12. Station 8 than provides for the passing of the vector to station 12 and station 12 accepts the vector from station 8 by communicating a data packet to another station. The performance mode sequence then consists of stations 8, 12 and n, as indicated by the double lines between stations 12 and n and between stations n and 8 and as indicated by the single line between stations 8 and 12.

0053An example of a splice-out transaction is also shown in Figure 10D, which also shows the time sequence for the transaction. In Figure 10D, station 12 initially receives the vector from from station 9. Station 12 then attempts to provide for the passing of the vector to station 15 after two process delay times (2 pd). After two additional (2) process delay times, station 15 communicates a data packet that station 12 should provide for the passing of the vector to station 20. After two further process delay times (2 pd), station 20 accepts the vector from station 20 by communicating a data packet to another station.

0054It may sometimes happen that a station is lost from the sequence. This is illustrated in the example shown in Figure 8. In the example shown in Figure 8, a sequence intially consists of stations 1, 2, 3, 4, 5, 6, 7 and 8. When the vector passes from station 1 to station 2, station 2 communicates a data packet to one or more of the other stations in the sequence and then attempts to provide for the passing of the vector to station 3. However, for one reason or another, station 3 may be temporarily or permanently out of the sequence. For example, the power to station 3 may be temporarily interrupted or there may be a malfunction of equipment at station 3.

0055As shown in Figure 2, station 3 would normally respond, after two process delay times (2 pd) from the passage of the vector from station 2, by communicating a data packet to another station or passing the vector. Since station 3 is incapable of communicating a data packet to another station because of a power loss or a malfunction, station 3 does not provide such a communication. Station 2 then provides for the passing of the vector again to station 3 after an additional period of two process delay times (2 pd).

0056If station 3 does not respond after such additional period of two (2) process delay times, station 2 again provides for the passing of the vector to station 3 for a third (3rd) time. If station 3 does not respond within two (2) process delay times from the third (3d) communication of the vector from station 2, station 4 may communicate a data packet that station 2 should pass the vector to station 4. Station 2 then splices station 3 out of the sequence and provides for the passing of the vector to station 4. Thus, after a total period of eight (8) process delay times (6 pd), station 4 communicates a data packet to another station. When station 2 thereafter splices station 3 out of the sequence, the system in Figure 8 includes stations 2, 4, 5, 6, 7 and 8.

0057It may occasionally happen that two (2) or more successive stations in a sequence are involuntarily lost temporarily or permanently from a sequence. For example, some one may have involuntarily or inadvertently opened a master switch controlling the operation of more than one successive station in a sequence. An example of this is shown in Figure 9 where stations 3 and 4 are temporarily or permanently lost from a sequence initially consisting of stations 1, 2, 3, 4, 5, 6, 7 and 8. If the example of Figure 9 corresponded to the example of Figure 8, station 3 would communicate with station 1 after station 1 attempted to provide for the passing of the vector to station 2 for three (3) successive periods each of two process delay times (2 pd) and station 2 failed to respond upon the third (3d) passage of the vector from station 1. However, in the example shown in Figure 9, station 3 is also lost from the sequence so that it cannot respond upon the third (3d) attempt by station 1 to provide for the passing of the vector.

0058Since neither station 2 nor station 3 has responded to the attempt by station 1 to provide for the passing of the vector in three (3) successive attempts, station 1 now attempts to provide for the passing of the vector to an imaginary station which may be considered as station "0". Station 1 does this by setting the identification of the next station in the sequence to zero (0). Every time that station 1 attempts to pass the vector to station 0, the other stations in the sequence decrement their identification by one integer in a register associated with such station. This register is identified in Figure 2A as "SNR", meaning "Station Number Relative".

0059The SNR register indicates the difference between the identification of the station providing for the passing of the vector anywhere and the identification of the station receiving this vector. For example, in the first attempt by station 1 to provide for the passing of the vector to station 0, station 4 decrements its Station Number Relative by one (1) integer from a value of 4 - 1 = 3 to a value of 3 - 1 = 2 so that its identification is now "2".

0060When station 1 has attempted two (2) successive times to provide for the passing of the vector to station 0, the identification of station 4 in the SNR register is now "1 " to indicate that it is the station next to station 1 in the sequence. Station 4 now communicates with station 1 to indicate that station 1 should splice station 4 into the sequence as the next station in the sequence and should pass the vector to station 4. Station 1 then provides for the passing of the vector to station 4 and the sequence in Figure 9 then constitutes stations 1, 4, 5, 6, 7 and 8.

0061Figure 10E illustrates another example of the loss of a station and also indicates the time periods involved in the recovery of the system from the loss of such station. In Figure 10E, station 9 provides for the passing of a vector to station 12, provides for the passing of a vector to station 12 a second time after the failure of station 12 to respond within a period of two process delay times (2 pd) and provides for a passing of a vector to station 12 a third time after a failure of station 12 to respond within a period of two process delay times (2 pd) to the third attempt by station 9. Station 9 then provides for the passing of a vector to imaginary station 0 to issue an invitation to the other stations in the sequence to become spliced to station 9.

0062Figure 10F also illustrates the time sequence for the successive operations in the "Lost Station Recovery" mode. In the embodiment shown in Figure 10F, station mm attempts to provide for the passing of the vector to the next station in the sequence. After two (2) process delay times, station mm again attempts to provide for the passing of the vector to such next station in the sequence. After two (2) additional process delay times (2 pd), station mm again attempts to provide for the passing of the vector to the next station in the sequence. This is indicated schematically in Figure 10F. After an additional period of two process delay times (2 pd) with no response from any other stations, station mm attempts to provide for the passing of the vector to imaginary station 0.

0063After each attempt by station mm to to provide for the passing of the vector to imaginary station 0 in Figure 10F, the registers in the stations (other than station mm) still in the sequence are decremented by an integer. Assume that, of the stations still in the sequence, station nn is the station next to station mm. When the count in the SNR register in station nn has been decremented to a value of "1", station nn sends an invitation to station mm in Figure 10F to splice station nn into the sequence. Upon receiving this invitation to splice, station mm splices station nn into the sequence and provides for the passing of the vector to station nn.

0064Figure 10F also illustrates how the system of this invention operates when the system is just starting to operate in the "power-up" mode or when all of the stations have been temporarily or permanently lost from the system. Under such circumstances, all of the stations attempt simultaneously to provide for the passing of the vector to station 0. All of the stations have an individual process delay time (pd) different from those of the other stations. This will cause the station with the shortest process delay time (pd) to assume control over the operation of the system.

0065Assume that station 1 has the shortest process delay time (pd). This will cause station 1 to provide for the passing of the vector to station 0 before any other station. Station 2 will accordingly decrement its count relative to station 1 by an integer and to communicate a splice packet to station 1. Station 1 accordingly splices station 2 into the sequence. Station 2 now provides for the passing of the vector to imaginary station 0 and every station except stations 1 and 2 decrements its count by an integer. The count in station 3 accordingly becomes decremented to a value where station 3 sends a splice package to station 2 and station 2 splices station 3 into the sequence. This continues until all of the stations have been progressively spliced into the sequence.

0066As previously described, a designation of "pmi" (representing "Performance Master Indicator") in the "Packet Data" portion of a packet for a station indicates whether such station will be an active station in a sequence. As previously indicated, the stations are capable of operating in different modes such as a set-up mode or a performance mode. A designation of "pma" (representing "Performance Mode Active") in the "Packet Data" portion of a packet for a station indicates the hierarchy of the operational mode which is currently involved.

0067In the set-up mode, all of the stations participate in the sequence regardless of their "Performance Master Indicator" (pmi). In the Performance Mode, only the stations with pmi indications are included in the sequence. As shown in Figure 6, not all of the stations in the set-up mode are necessarily included in the performance mode since the performance mode is at a higher level than the set-up mode.

0068Assume that the stations in a sequence are operating in the set-up mode. In order to ascend to the performance mode, any station in the set-up mode can communicate that the performance mode should be activated. However, in order to do this, such station has to pass a vector with the desired "pma" designation in the "Packet Data" portion of the vector packet. Such station can then convert the operation to the performance mode by including this value as the "pma" value in the next vector it transmits. The stations then operate in the performance mode.

0069For example, in Figure 7, stations 1, 2, 3, 4, 5, 6, 7 and 8 are in the set-up mode (as indicated by solid wide lines between the stations) but only stations 1, 5 and 8 are in the performance mode (as indicated by broken lines between the stations). A register shown in Figure 2A as "PNID" (meaning Next performance Identification") is provided for each individual one of the stations in the performance mode to indicate the next station in the performance mode - i.e., the station to which each individual station provides for the passing of the vector in the performance mode..

0070When the stations (such as stations 1, 5 and 8) in Figure 7 are operating in the performance mode, other individual stations with an occasional need to send information may include a pma designation in the "Packet Data" portion of a packet. This allows such individual stations to enter into the sequence of the performance mode when the stations in the performance mode have sequenced to a position where such individual stations can be spliced into the sequence. When such individual stations have completed the communication of information to another station, or other stations, in the sequence, they operate to splice themselves out of the sequence in the manner shown in Figure 5 and discussed above.

0071In order for the stations (such as the stations 1, 5 and 8 in Figure 7) to continue to operate in the performance mode in successive cycles of operation, one of the stations has to indicate on a positive basis in each such cycle that it desires to continue the operation of the sequence in the performance mode. One of the stations does this by communicating a pmi indication to the other stations in the sequence. If none of the stations in the sequence sends a pma communication in a cycle of operation, the sequence reverts to the set-up mode.

0072The system disclosed above has certain important advantages. These advantages provide the systems of this invention with a considerably enhanced flexibility in the operation of the system in comparison to the system of the prior art. For example, the system of this invention can adjust the stations in a sequence to splice stations into, or splice stations out of, the sequence without affecting the operation of the system. The system of this invention provides these station adjustments or flexibilities in such a way that the system continues to operate without any noticeable interruptions in the operation of the system. When the system is operating to generate data relating to music, this is important in insuring that the listener will continue to hear the music without any noticeable pause or interruption.

0073The adjustment in the operation of the system of this invention without affecting or interrupting the operation of the sequence may be seen from the following different examples: <ul id="ul0002" list-style="none"><li>1. Any station not in a sequence may splice itself into the sequence. Furthermore, this splicing occurs at a proper time in the sequence depending upon the position of the station in the sequence.</li><li>2. Any station may splice itself out of a sequence. Furthermore, such splicing occurs at a proper time in the sequence depending upon the position of the station in the sequence.</li><li>3. Any station may be spliced out of a sequence if it does not accept the vector from a previous station in the sequence within a predetermined time. Furthermore, such splicing occurs at a proper time in the sequence depending upon the position of the station in the sequence.</li></ul>

0074The system of this invention also has other important advantages. For example, it is able to provide a selective communication between stations. This may be seen from the following: <ul id="ul0003" list-style="none"><li>1. A station receiving the vector is able to communicate a data packet to any of the other stations in a sequence.</li><li>2. A station receiving the vector is able to communicate a data packet to any selected group of stations in a sequence.</li><li>3. A station receiving the vector is able to broadcast a data packet to all of the other stations in a sequence.</li></ul> In all of the above communcations, the operation of the system is not affected.

0075The system of this invention is also advantageous under conditions which would be considered as catastrophic in the systems of the prior art. For example, even when two (2) or more successive stations are lost from a sequence, the system of this invention is able to patch the system without affecting or interrupting the oeration of the system.

0076The system of this invention also follows the same procedure as discussed in the previous paragraph when power is first applied to the system. In this way, the system is able to become automatically operative when power is first applied to the system. Furthermore, the system is able to become operative in a minimal period of time and in a proper succession of stations under such circumstances.

0077The system of this invention is also able to become converted (or switched) automatically between different modes of operation without any noticeable interruption in the operation of the system. For example, the system is able to become converted from a set-up mode to a performance mode without any interruption in the operation of the system. The system is also able to operate in the performance mode for any desired period of time and to revert to the set-up mode whenever it is no longer desired to operate the system in the performance mode.

0078The program for operating the system of this invention is shown in Exhibit A, which is attached to this specification and is considered as forming a part of this specification. Applicant believes that a person of ordinary skill in the art will be able to understand this program without further explanation, particularly in view of the above description of the construction and operation of the system of this invention.

0079Although this invention has been disclosed and illustrated with reference to particular embodiments, the principles involved are susceptible for use in numerous other skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

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