Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
  • H04L12/40—Bus networks
  • H04L12/403—Bus networks with centralised control, e.g. polling
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B3/00—Line transmission systems
  • H04B3/54—Systems for transmission via power distribution lines
  • H04B3/542—Systems for transmission via power distribution lines the information being in digital form
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
  • H04B2203/5408—Methods of transmitting or receiving signals via power distribution lines using protocols
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
  • H04B2203/5416—Methods of transmitting or receiving signals via power distribution lines by adding signals to the wave form of the power source
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5429—Applications for powerline communications
  • H04B2203/5445—Local network
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5429—Applications for powerline communications
  • H04B2203/5458—Monitor sensor; Alarm systems
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5462—Systems for power line communications
  • H04B2203/5491—Systems for power line communications using filtering and bypassing
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5462—Systems for power line communications
  • H04B2203/5495—Systems for power line communications having measurements and testing channel

Definitions

• the present invention relates generally to comput ⁇ erized data communications systems, and more specifically to a computer system for monitoring a plurality of remote elec ⁇ trically operated devices such as slot machines wherein the data bus incorporates the electrical power lines supplying the remote devices.
• Communication may occur between any two devices, but in the preferred embodiment, communication is initiated by the central computer which sequentially polls individual sensor modules within the slot machines on a regular cyclical basis.
• Each slot machine sensor module is assigned a serial number for identification purposes.
• the polling signal includes a preamble of pure carrier frequency, followed by the serial number of the device being polled, followed by the data (or instructions) defining the message content.
• Each data link has its own clock for generating a pulse train at a frequency very close to the common carrier frequency, and includes means for bringing its own carrier frequency pulse train approximately into a predetermined phase relationship with the carrier train that is appearing on the power lines. This is typically done by stepping the phase by 90° incre ⁇ ments until the local clock is in proper phase.
• serial number portion of the message begins, all data links are synchronized with the carrier in order to be able to interpret the serial number.
• each device ascertains whether the message is destined for it, and if so, receives and acts on the message.
• the message from the main computer requests the transmission from the remote sensor of some data. If the transmission from the remote sensor occurs substantially immediately, the central computer is already synchronized with the sensor.
• the electrical power distribution lines represent an extremely noisy environment and thus an unlikely medium for messages where error free data transmission is a prerequisite.
• the noise on the electrical lines arises from the various device drawing electrical power such as motors with arcing brushes and solid state control units characterized by extremely sharp changes in current conduction. While some potential sources of electrical interference may be filtered, sharp pulses contain power at virtually all frequencies, and canno be filtered.
• each data link has means for changing (for example, halving) the carrier frequency if it is determined that messages at the original frequency are not getting through without error. This capability lowers the probability that data transmission is totally interfered with.
• the electromechanical signals regarding the state of the slot machine are monitored by a plurality of opto/isolators assemblies. While an electrical connection i made to sense the electrical signals originating in the machine, the connection is one-way; while the sensor module can respond to the AC signals, it cannot influence them. Th passage of a coin through the machine is monitored by a plur
• Fig. 2 is a block diagram of the communication system utilizing the electrical power distribution lines
• Figs. 7A and 7B taken together, form a circuit schematic of the communications processor; and Fig. 8 is a diagram illustrating the system message format.
• DETAILED DESCRIPTION OF THE INVENTION Overview provides a computer ⁇ ized monitoring system which uses the power lines that pro ⁇ vide electrical power to the monitored devices as the physi ⁇ cal data communications medium of the computer data bus.
• the description that follows will be with reference to monitoring a plurality of slot machines in a casino.
• Fig. 1 is a schematic block diagram showing a typical power distribution system for a hypothetical casino.
• Each of reels 199 is pro ⁇ vided with marker such as a contrasting dot 225 at a prede ⁇ termined position, preferably near an edge of the cylindrical surface of reel 199.
• the basic purpose of the circuitry is to use dot 225 as a reference and to count the number of symbols passing after the dot in order to gain a precise indication of the reel position.
• a 700 Hz signal is inter ⁇ mittently generated at phototransistor 227b during the per- iods that light is being reflected.
• the signals from photo ⁇ transistor 227b are passed through 700 Hz band pass circuitry 235, and thence to 700 Hz detection circuitry 240.
• Circuitry 235 is characterized by a gain of 5 and value of 3 to amplify and filter the signals in order to provide a clean 700 Hz signal during those intervals when light is being reflected.
• Detection circuitry 240 tuned to the same 700 Hz frequency provides an output signal pulse for each picture that goes by sensor 227. These pulses are passed to a 5-bit counter 245 which provides a numeric representation of the position of reel 199.
• Communication processor 67 comprises a microproces- sor 260 which is coupled to central computer data link 70 in the same manner that microcomputer 85 is coupled to slot machine data link 87.
• Microprocessor 260 communicates to a universal synchronous/asynchronous receiver and transmitter (hereinafter USART) 262.
• USART 262 transmits signals on lines 265 and 267 to the LED (input) side of an opto/isolator 270, and receives signals on lines 272 and 273 from the phototransistor (output) side of an opto/isolator 274.
• Group Poll 1 (2 bit times) for each of 16 machines
• Command type 8 is requests the return of a 24-bit counter representative of the number of coins that have gone into the safe.
• Command type 9 requests the return of a 16-bit counter representative of the number of coins that were paid out on the last cycle.
• Command type 11 requests the return of a 24-bit data check code which is the sum of the number of coins in, the number of coins out, the number of coins in the hopper, and the number of coins in the safe. It is used to detect that one of these quantities changed since the last time the machine was interrogated.
• Command type 12 instructs microcomputer 85 to select the alternate carrier frequency from whenever it may be at the time, and, when it gets to that other carrier fre ⁇ quency, to return the status register.
• Command type 13 instructs microcomputer 85 to clea the error code and return the status, but this will only occur if the previous command to the particular microcompute
• OMPI VT O was a type 3 command to return the error code. Otherwise th response to the command is merely to return the status register but not to clear the error code.
• Command type 14 requests return of the 24-bit cycl number of the last cycle on which an error occurred.
• the present inven ⁇ tion provides a computerized monitoring and communications system that is characterized by simplicity and reliability while providing high data transfer rates under highly inhos ⁇ pitable conditions. While the above provides a full and complete disclosure of the preferred embodiments of the invention, various modifications, alternate constructions, and equivalents may be employed without departing from the true spirit and scope of the invention. For example, the system is clearly applicable to remote devices other than slot machines. Therefore, the above description and illus ⁇ trations should not be construed as limiting the scope of th invention which is defined by the appended claims.

Landscapes

• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Power Engineering (AREA)
• Pipeline Systems (AREA)
• Synchronisation In Digital Transmission Systems (AREA)
• Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
• Remote Monitoring And Control Of Power-Distribution Networks (AREA)
• Small-Scale Networks (AREA)

Applications Claiming Priority (1)

Publications (1)

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ID=22168229

Family Applications (1)

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• 1982
  • 1982-09-27 AU AU90504/82A patent/AU555336B2/en not_active Ceased
  • 1982-09-27 WO PCT/US1982/001334 patent/WO1984001482A1/en unknown
  • 1982-09-27 JP JP50318182A patent/JPS59501808A/ja active Pending
  • 1982-09-27 GB GB08412482A patent/GB2140659B/en not_active Expired
  • 1982-09-27 EP EP19820903219 patent/EP0119999A1/de not_active Withdrawn

Non-Patent Citations (1)

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