JPH11120424A - Controller for vending machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To normally attain communication between a main control part and terminal control parts while reducing costs by using an imprecise but inexpensive CR oscillation circuit for the pulse oscillation circuit of a terminal control part. SOLUTION: A main control part 1 controls plural terminal control parts 2, 3,... for individually controlling each part of a vending machine through a communication line 4. At that time, the main control part 1 adds the first start bit in an L level and the second start bit in an H level to the head of transmission data for operating data transmission. Then, the terminal control parts 2, 3,... receive such data from the main control part 1, count the output pulses of CR oscillation circuits 22, 32,... in a period since the falling of the first start bit until the rising, and operate data reception or transmission by using the number of count as the length of one bit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vending machine control apparatus in which each terminal of a vending machine is controlled by a terminal control unit, and such a terminal control unit is controlled by a main control unit. It is.

[0002]

2. Description of the Related Art A vending machine control device is divided into a main control unit and a plurality of terminal control units, and the main control unit and each terminal control unit are connected by serial communication. As a communication method, a start-stop synchronization method is adopted.
In the start-stop synchronization system, an oscillation circuit for generating a pulse of a constant frequency is provided in both the main control unit and the terminal control unit, and communication is performed with timing.

FIG. 8 is a schematic configuration diagram of a conventional vending machine control device. The main controller 1 controls the terminal controllers 2, 3,... While communicating via the communication line 4. The main controller 1 and the terminal controllers 2 and 3 are controlled by the CPUs 11, 21 and 31, respectively.
They are provided with oscillating circuits 12, 24 and 34, each of which generates a pulse of a constant frequency.

[0004] From the main control unit 1 to the terminal control units 2, 3, ...
When the data is transmitted to, the data is transmitted in a format as shown in FIG. If the communication speed is 4800 bps, the time of one bit is 1 ÷ 4800 ≒ 208.
3 μs. That is, a start bit (fixed to "L"), D0 to D7, a parity bit, and a stop bit (fixed to "H") are sequentially output every 208.3 .mu.sec.

On the other hand, as shown in FIG. 10, the terminal control units 2, 3,... Receive the falling edge of the start bit and then temporarily receive the signal due to the influence of noise or the like. 208.3 to eliminate the case of “L”
At the time when 1/2 of .mu.sec, that is, 104.15 .mu.sec has elapsed, it is checked whether or not the start bit is "L". Thereafter, D0 to D7 every 208.3 .mu.sec.
, Parity bit, and stop bit, and if the parity bit and the stop bit are normal, the data is processed as correct data.

Conventional documents relating to such a vending machine control device include, for example, Japanese Patent Publication No. 62-35154.
(G07F 9/00).

[0007]

In the above-mentioned conventional vending machine control device, when the terminal control units 2, 3,... The sampling timing is determined based on the pulse output from the oscillation circuit corresponding to the width of.
In this case, if the time error of the pulse exceeds about ± 2.5%, the timing of sampling is shifted and communication cannot be established. That is, the terminal control unit 2,
When low-precision oscillation circuits such as CR oscillation circuits (oscillation circuits including capacitors and resistors) are used as the oscillation circuits 24 and 25 of 3,..., The oscillation frequency greatly fluctuates due to temperature changes and the like. Communication fails.

Therefore, conventionally, the oscillation circuit 2 of the terminal control unit is used.
Oscillation circuits using high-precision ceramic oscillators or crystal oscillators were used for 4, 25,
An oscillation circuit using such a ceramic oscillator or a crystal oscillator has a problem that the price is high.

The present invention solves such a problem, and uses a low-precision but inexpensive CR oscillation circuit for generating a clock pulse for the terminal control unit while reducing the cost while using the main control unit and the terminal. The communication between the control units is intended to be performed normally.

[0010]

According to a first aspect of the present invention, there is provided a vending machine control apparatus comprising: a plurality of terminal control units for individually controlling each unit of the vending machine; A vending machine control device comprising: a main control unit that controls and controls a control unit through a communication line, wherein the terminal control unit sets a reference time of communication used in the terminal control unit to the main control unit. Is determined on the basis of data transmitted from. In this way, communication between the main control unit and the terminal control unit can be performed normally while reducing costs by using an inexpensive CR oscillation circuit for pulse generation of the terminal control unit. Can be.

According to a second aspect of the present invention, in the vending machine control device, the main control unit includes a first start bit fixed to one of an L level and an H level at the beginning of the transmission data; Data transmission is performed with a second start bit fixed at a level opposite to the first start bit, and the terminal control unit sets the reference time of communication used in the terminal control unit to the first start bit. Is determined based on the time from the fall of the start bit to the rise or the time from the rise to the fall. In this way, each time data is sent, the communication reference time can be determined based on the bit length at that time, and communication stability can be ensured.

According to a third aspect of the present invention, in the vending machine control device, a reference signal line is provided between the main control unit and the terminal control unit, and the main control unit uses the reference signal line to transmit transmission data. The terminal control unit transmits a reference signal corresponding to the length of 1 bit, and the terminal control unit determines a reference time of communication used in the terminal control unit based on the reference signal. With this configuration, even when the communication format is fixed to the conventional one and cannot be changed, the reference time of the communication used in the terminal control unit is accurately determined based on the reference signal transmitted from the main control unit. Can be. As a result, communication between the main control unit and the terminal control unit can be performed normally while reducing the cost by using an inexpensive CR oscillation circuit as the oscillation circuit of the terminal control unit.

According to a fourth aspect of the present invention, in the vending machine control device, the main control unit transmits the data at a different communication speed according to a terminal control unit that transmits data. With this configuration, the communication speed can be changed according to the amount of data to be transmitted to the terminal control unit, and communication efficiency can be improved.

The control device for a vending machine according to claim 5, wherein the terminal control section counts a pulse output from the oscillation circuit and counts a pulse output from the oscillation circuit to count a predetermined time. And determining the relationship between the pulse count and time in the control timer based on data output from the main control unit. In this way, even if an inexpensive CR oscillation circuit is used, the accuracy of the control timer can be ensured.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a schematic configuration diagram of a first embodiment. As the oscillation circuits of the terminal control units 2 and 3, in the control device of the conventional vending machine, as described above, an expensive ceramic oscillation circuit was used. On the other hand, in the present invention, the oscillation circuit 12 of the main control unit 1 uses an oscillation circuit using a high-precision ceramic oscillator or a crystal oscillator, but the oscillation circuit of the terminal control units 2, 3,. Inexpensive oscillation circuits such as CR oscillation circuits 22 and 32 are used.

The oscillation frequencies of the CR oscillation circuits 22 and 32 greatly fluctuate under the influence of the ambient temperature and the like. Therefore, data in a format as shown in FIG. 9 transmitted from the main control unit 1 at 4800 bps is transmitted to the terminal control units 2 and
In the case of receiving on the 3,... Side, in order to take in data at the timing as shown in FIG. The actual time fluctuates.

Therefore, in this embodiment, the data format when transmitting from the main control unit 1 is as shown in FIG. That is, a start bit 1 fixed at "L" and a start bit 2 fixed at "H" are added to the head of the data, and then data D0 to D7, a parity bit, and a stop bit (fixed at "H") are added. Output.

In the terminal control units 2, 3,...
While the start bit 1 is “L”, the CR oscillation circuits 22, 32,... Of the terminal control unit oscillate in order to measure the time of one bit of the data sent from the main control unit 1. Count how many pulses there are. For example,
Assuming that the oscillation frequency of the CR oscillation circuits 22 and 32 is 1 MHz, one pulse is output every 1 microsecond. Therefore, as shown in FIG. 3, when the counting of the pulses output from the CR oscillation circuits 22 and 32 starts at the time T0 when the start bit 1 falls, and the counting ends at the time T1 when the start bit 1 rises, 208.
3 (μsec) ÷ 1 (μsec) ≒ 208 (count).
The count number is stored as a one-bit length.

Next, the communication line 4 is sampled at a time T2 after 208 (counts) .times.1.5 = 312 (counts) from the time T1 when the start bit 1 rises to obtain data D0. Thereafter, the communication line 4 is sampled every 208 counts, and data D1, D2,.
..., D7, parity bit, and stop bit are obtained.

When data is transmitted from the terminal control unit to the main control unit, the length is set to 1 bit using the latest count number obtained at the time of reception. That is, in the above example,
Transmission is performed with 208 counts as 1 bit length.

The oscillation frequency of the CR oscillation circuit fluctuates under the influence of the ambient temperature and the like. This will be described with reference to FIG. FIG. 4 shows a case where the oscillation frequency of the CR oscillation circuit fluctuates within a range of ± 25%.
For example, if 100% is 1 MHz, then, as described above, 208 counts are processed as 1-bit length.

On the other hand, when the oscillation frequency of the CR oscillation circuit becomes 75%, that is, 0.75 MHz, the interval between oscillation pulses becomes 1.33 μsec, and the number of pulses per bit at 4800 bps is 208.3. (Μsec) ÷ 1.3
3 (μsec) ≒ 156. Therefore, the count number 156 is stored, and thereafter, the communication line is sampled every 156 counts, and the data D1, D2,.
..., D7, parity bit, and stop bit are obtained.
Also, when transmitting, the transmission is performed with 156 counts as 1 bit length.

When the oscillation frequency of the CR oscillation circuit becomes 125%, that is, 1.25 MHz, the interval between oscillation pulses becomes 0.8 μs, and the number of pulses per bit at 4800 bps is 208.3 ( μs) ÷ 0.8
(Μsec) ≒ 260. Therefore, the count number 260 is stored, and thereafter, the communication line is sampled every 260 counts, and the data D1, D2,.
・, D7, parity bit and stop bit are obtained. Also, when transmitting, the transmission is performed with 260 counts as the length of 1 bit.

As described above, the length of one bit is measured by the count number of the oscillation circuit based on the start bit 1 of the received data, and the processing is performed in accordance with the count. Communication becomes possible.

In the first embodiment, the start bit 1 is set at the L level and the start bit 2 is set at the H level. However, the present invention is not necessarily limited to this. As shown in FIG. 1 may be at the H level and the start bit 2 may be at the L level.

(Second Embodiment) FIG. 6 is a schematic configuration diagram of a second embodiment. In this embodiment, a reference signal line 5 is provided in addition to the two communication lines 4 and 4, thereby
The reference signal related to the bit length is provided. The reference signal has a pulse width W corresponding to the length of one bit as shown in FIG. Then, in the terminal control unit, while the reference signal is “L”, the C of the terminal control unit is
The number of pulses oscillated by the R oscillation circuits 22, 32,... Is counted, and the length of one bit is measured. The pulse width W need only be determined by the length of one bit based on the pulse width W. Therefore, the pulse width W does not necessarily need to be set to one bit length, and may be set to １ ／, １ ／, or the like of one bit. .

According to this embodiment, communication can be performed with the conventional communication format as shown in FIG. Therefore, if the communication format of the CPU is limited to that of FIG.
By employing this embodiment, the same effects as those described above can be obtained.

In the conventional vending machine control device, it was necessary to communicate at a fixed communication speed of, for example, 4800 bps. However, according to the present invention, there is no need to fix the communication speed. . That is, the terminal control unit according to the present invention can measure the length of one bit regardless of the communication speed of the transmitted data and can receive the data in accordance with the length, so that the main control unit 1 The communication speed can be changed according to the control unit. For example,
960 for the terminal control unit that transmits a large amount of data.
The communication speed is increased such as 0 bps so that the communication time does not become longer. For a terminal control unit that transmits a small amount of data, the communication speed is reduced such as 4800 bps and accurate communication is performed. In this case, more efficient communication becomes possible.

May be controlled using a timer. In such a case, the pulses output from the CR oscillation circuits 22, 32,... This will constitute a control timer. At this time, if the oscillation frequency of the CR oscillation circuits 22, 32,... Fluctuates, the control time fluctuates and normal control cannot be performed. For example, when the sales control unit sets the energization time of the product unloading solenoid to 10 milliseconds, an error occurs in the control timer, and the energization cannot be performed for a necessary time.
There is a possibility that the product cannot be carried out or that power is supplied for an unnecessarily long time and power and time are wasted.

To cope with such a situation, the control timer can be corrected using the start bit 1 in the first embodiment and the reference signal in the second embodiment. That is, since the length of the start bit 1 and the reference signal of the data sent from the main control unit 1 is always constant, the unit time is determined based on the number of pulses counted during the period when the start bit 1 is "L". You can see the count number per hit. By using the count number per unit time, an accurate timer can be obtained.

[0032]

Since the present invention is configured as described above, it has the following effects. In the control device for a vending machine according to the first aspect, the terminal control unit determines the reference time of communication used in the terminal control unit based on highly accurate data transmitted from the main control unit. Therefore, inexpensive CR for pulse generation of the terminal control unit
Communication between the main control unit and the terminal control unit can be performed normally while reducing cost by using the oscillation circuit.

In the control device for a vending machine according to a second aspect of the present invention, the main control unit attaches an L-level first start bit and an H-level second start bit to the head of the transmission data. Then, the terminal control unit determines the reference time of communication used in the terminal control unit based on the time from the fall to the rise of the first start bit. As a result, each time data is transmitted, the communication reference time can be determined based on the bit length at that time, and communication stability can be ensured.

According to a third aspect of the present invention, there is provided a vending machine control device, wherein a reference signal line is provided between a main control unit and a terminal control unit, and the main control unit uses the reference signal line to transmit transmission data. 1
A reference signal corresponding to the bit length is transmitted, and the terminal control unit determines a reference time of communication used in the terminal control unit based on the reference signal. As a result, there is no need to change the communication format, and even when only the conventional communication format can be adopted, the main control unit can reduce the cost by using an inexpensive CR oscillation circuit for the oscillation circuit of the terminal control unit. Communication between the terminal control unit and the terminal control unit can be performed normally.

In the control device for a vending machine according to the fourth aspect, the main control unit transmits the data at a different communication speed in accordance with the terminal control unit for transmitting data. The communication speed can be changed according to the amount of data to be transmitted and the like, and communication efficiency can be improved.

Further, in the control device for a vending machine according to the present invention, the relationship between the count number of the output pulse of the control timer for measuring time based on the output pulse of the pulse oscillation circuit of the terminal control unit and the clocking time. Is determined based on data output from the main control unit, so that a low-cost CR
Even when an oscillation circuit is used, the accuracy of the control timer can be ensured.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment.

FIG. 2 is a diagram illustrating a communication format according to the first embodiment.

FIG. 3 is a diagram showing sampling timing of received data in a terminal control unit.

FIG. 4 is a diagram illustrating a relationship between a communication format and an oscillation pulse in the first embodiment.

FIG. 5 is a schematic configuration diagram of a second embodiment.

FIG. 6 is a schematic configuration diagram of a second embodiment.

FIG. 7 is a diagram illustrating a method of determining a sampling interval of received data in a second embodiment.

FIG. 8 is a schematic configuration diagram of a conventional vending machine control device.

FIG. 9 is a diagram showing a communication format in a conventional vending machine control device.

FIG. 10 is a diagram showing sampling timing of received data in a conventional vending machine control device.

[Explanation of symbols]

 4 communication line 5 reference signal line 12, 24, 34 oscillation circuit 13 buffer 22, 32 CR oscillation circuit

Continuation of front page (72) Inventor Yasuhiro Yamazaki 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (5)

[Claims] An apparatus for controlling a vending machine, comprising: a plurality of terminal controllers for individually controlling the respective units of the vending machine; and a main controller for controlling the plurality of terminal controllers integrally through a communication line. Wherein the terminal control unit determines a reference time for communication used in the terminal control unit based on data transmitted from the main control unit. 2. The method according to claim 1, wherein the main control unit includes:
First level fixed to either L level or H level
And a second start bit fixed at a level opposite to that of the first start bit to transmit data, and the terminal control unit sets a reference time for communication used in the terminal control unit. 2. The control device for a vending machine according to claim 1, wherein the control unit determines the value of the first start bit from the fall to the rise of the first start bit or the time from the rise to the fall of the first start bit. 3. A reference signal line is provided between the main control unit and a terminal control unit, and the main control unit transmits a reference signal corresponding to one bit length of transmission data using the reference signal line. And
The vending machine control device according to claim 1, wherein the terminal control unit determines a reference time of communication used in the terminal control unit based on the reference signal. 4. The vending machine control device according to claim 1, wherein the main control unit changes the communication speed according to a terminal control unit that transmits data and transmits the data. 5. The terminal control unit, comprising: a pulse oscillation circuit;
A control timer that counts pulses output from the oscillation circuit and counts a predetermined time, and outputs the relationship between the number of pulses and time in the control timer from the main control unit. 5. The vending machine control device according to claim 1, wherein the determination is made based on data obtained from the vending machine.