Machine operating condition monitoring system

Abstract

This invention relates to a system for monitoring the condition and operation of remotely located machines, such as coin-operated vending machines. In one embodiment, switches in each machine convert operating conditions into a binary digital word for that machine, which is stored temporarily. Such words for a plurality of machines are then transferred to a memory, whence they are retrieved, coded as to machine number and transmitted via telephone line to a control processing unit where the various machine conditions are recorded and displayed.

Description

This invention relates to a system for monitoring the operating condition of remotely located machines and the like, and is particularly adapted for monitoring the operating condition and amount of sales of a large number of remotely located coin-operated vending machines.

Coin-operated vending machines are typically scattered over a fairly extensive geographic area, and maintaining them fully stocked and in operative condition poses a substantial problem. Usually the machines are visited in rotation by a route man, who stocks the machines and reports any faulty operation so that a repairman may be sent. Loss of revenue due to empty or inoperative machines is considerable, and could be greatly reduced by knowing immediately which machines need attention, and additional savings could be effected by more efficient use of the routemen, obviating the waste of their time in visiting operative machines that need no restocking. Further, the routeman generally collects the money from the machine, and there is at present no reliable way of confirming his count.

The above problem could be removed or at least greatly diminished if there existed a practical way of obtaining, at some central location, an immediate indication of any failure or shortage identified as to a particular machine, and a count of the money taken in by each machine. This invention provides such a practical system.

In the monitoring system of this invention, switches in the monitored machines generate binary condition indications. The binary information generated by the switches in each machine is stored in a register attached to the machine. Then the binary data from each machine register, for a local group of machines, is sequentially fed to a local storage unit called a data concentrator. This data is compared with the data previously received from each machine, and any changes are flagged before the data is stored. Then, transmitting data only changed data from machines where changes have recently occurred is routinely transmitted selected for transmission from the concentrator RAM, once every ten minutes the entire slate of data stored in each RAM is sent. This complete data dump is initiated by 10 minute timer 31 (FIG. 3) and is accomplished as indicated in FIG. 9 by starting at a RAM word known to be a data word (location 5), each data word is removed and the flag bit set. Thus all flags are set, even though the data may not have changed, and upon the next SEND DATA signal the entire slate of RAM data will be sent.

The initiation of operation of the system is shown in the "power-up" flow diagram of FIG. 7. It will be seen that it consists in setting all zeros into the RAM, clearing all registers and counters, and setting the address counter 25 to 0.

The above embodiment is merely examplary and various changes and modifications may be made without departing from the scope of the invention, which is defined solely in the appended claims.

Claims

1. A system for monitoring a plurality of machines having widely spaced locations comprising:

a plurality of binary sensors connected to each machine;

a plurality of local data storage and processing units, each corresponding to a separate group of machines and connected to every machine in that group;

means to sequentially feed binary information from sensors in each machine of a group to said local data storage and processing unit corresponding to that group;

comparison means in said local data storage and processing unit for comparing received sensor information with previous information received from the same sensor and determining and indicating the existence of a change;

a central processing unit;

scanning means for scanning said local data storage and processing units and selectively retrieving from them only changed information; and

transmission means for transmitting said changed information to said central processing unit.

2. The system of claim 1 wherein further:

said binary sensors comprise sensors connected to indicate at least one machine operation;

said local data storage and processing units each contain operation count means connected to said comparison means for counting the number of operations of said at least one machine operation and operation storage means for storing the result of said operation count means; and

said scanning means retrieves from each said local data storage and processing unit any changed operation count information.

3. The system of claim 1 wherein further:

said binary sensors comprise sensors connected to indicate the existence of at least one machine condition requiring attention; and

said central processing unit contains indicating means responsive to the existence of changed machine condition information for providing an indication that a machine needs attention.

4. The system of claim 1 wherein further:

said binary sensors comprise sensors connected to indicate at least one machine operation and to indicate the existence of at least one machine condition requiring attention;

said local data storage and processing units each contain operation count means connected to said comparison means for counting the number of operations of said at least one machine operation and operation count storage means for storing the result of said operation count means;

said scanning means retrieves any changed operation count information from each said local data storage and processing unit; and

said central processing unit contains indicating means responsive to the existence of changed machine condition information for providing an indication that a machine needs attention.

5. The system of claim 1 wherein:

said means to sequentially feed binary information from sensors in each machine to a local data storage and processing unit includes

a. shift register storage means associated with each machine for storing information from each said sensor connected to that machine; and

b. means associated with each said local storage and processing unit for sequentially feeding information from all associated machine shift register storage means to said local data storage and processing unit.

6. The system of claim 1 wherein at periodic intervals all of the information stored in said local data storage and processing units, whether recently changed or not, is transmitted to said central processing unit.

7. The system of claim 1, including further origin identification means for adding to said information selected for transmission via said transmission means an identification of the location from which said information was obtained.