JP3662707B2 - Communication control method for refrigerated showcase - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication control method for a refrigerated showcase.
[0002]
[Prior art]
As is well known, a refrigerator-freezer showcase is a device in which a compressor is connected to a cooler installed in the showcase, the refrigerant is sent from the compressor, and the inside of the showcase is cooled by the cooler. In stores such as supermarkets where multiple cases are installed, the compressors are installed separately from the compressor, and the refrigerators of multiple refrigerator-freezer showcases are connected to a single compressor. In some cases, a refrigerator is shared by a plurality of coolers to form a refrigeration cycle for each showcase, and a plurality of such compressors are installed.
[0003]
On the other hand, it is necessary to remove frost attached to the cooler at regular intervals so that the cooling capacity does not decrease, but in such a case, since a plurality of coolers are connected to one compressor, Multiple coolers must be defrosted at the same time.
[0004]
In a plurality of freezer / refrigerated showcases having the above-described refrigeration cycle, as the control means for defrosting the cooler installed for each showcase, for example, as shown in FIG. Each of the showcase controllers 4a, 4b, 4c,... 4n provided with defrosting means and communication transmission / reception means is provided, and the defrosting processing of the plurality of showcase controllers 4a, 4b, 4c,. One defrosting controller 3a or 3b to be controlled is connected to each showcase controller 4a, 4b, 4c,... 4n via the transmission line 2, and each group of a plurality of showcase controllers 4a, 4b, 4c,. A plurality of defrost controllers 3a or 3b connected one by one are provided, and the plurality of defrost controllers 3a and 3b are connected to one central controller. There are means of communication control to connect the transmission line 2 to the controller 1.
[0005]
In order to control the defrosting of the cooler installed in each refrigerated display case by such communication control means, the time signal 5 from the center controller 1 is transmitted via the transmission line 2 at the start time of the defrosting operation. Input to the defrost controllers 3a and 3b simultaneously. The defrost controllers 3a and 3b receive the input of this signal, and remove the address by a specific signal of the defrost controllers 3a and 3b to the plurality of showcase controllers 4a, 4b, 4c,. The frost start signals 6 and 7 are transmitted simultaneously via the transmission line 2.
[0006]
Each of the showcase controllers 4a, 4b, 4c,... 4n is removed by a defrost start signal 6, 7 input from the defrost controllers 3a, 3b to which the showcase controllers 4a, 4b, 4c,. The frost starts.
[0007]
In this case, since a plurality of defrosting start signals 6 and 7 having different addresses are simultaneously transmitted from the defrosting controllers 3a and 3b through the same transmission line 2 as shown in FIG. Signals 6 and 7 will collide.
[0008]
In order to cope with this, conventionally, priorities are set in advance in the addresses of the signals transmitted from the defrost controllers 3a and 3b, and a signal with the address of the partner that collided on the communication line is received. The other party's address attached to is compared with its own address to determine the priority, and if the result of the determination is that the signal of its own address has priority, defrosting start signals 6 and 7 are transmitted.
[0009]
On the other hand, if the signal assigned with its own address has a lower priority, its own transmission is suspended until the other party's communication is completed, and transmission is started simultaneously with the end of the other party's communication. When a signal collision occurs on the communication line, this processing is repeated and transmitted sequentially.
[0010]
[Problems to be solved by the invention]
In such a communication control method in which the priority order of signals is determined each time a signal collision occurs on the communication line and only one defrost controller can transmit, each time a transmitted signal is transmitted. Since the order determination work is performed and the collision depends on the state of each defrost controller, the defrost controller to be surely preferentially transmitted cannot be determined by the unit of the controller, and there is an uncertain element in the communication. In some cases, there is a problem in reliability, and communication efficiency is not good.
[0011]
In particular, in the case of transmission of a defrost start signal, the defrost signal is always transmitted from multiple defrost controllers simultaneously on the same transmission line by the time report signal from the center controller, and the signals frequently collide. There are always regular time periods. For this reason, the communication line is congested, a time zone in which signal collision frequently occurs and a time zone in which there is no signal on the communication line occur, and the communication efficiency of the communication line is not good.
[0012]
The object of the present invention is to eliminate the inconveniences of the conventional example, to minimize the collision of signals on the communication line, to reduce the uncertainties on the communication and to improve the reliability of the communication. An object of the present invention is to provide a communication control method for a refrigerated showcase capable of reducing the busy state and leveling the communication state and improving the communication efficiency.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention firstly provides a showcase controller provided with a defrosting means and a communication transmitting / receiving means for each freezing / refrigeration showcase of a plurality of freezing / refrigeration showcases, A defrost controller is connected to each showcase controller via a transmission line, and one defrost controller is connected to each showcase controller group. In a communication control method for a refrigerated showcase in which a plurality of units are provided and the plurality of defrost controllers are connected to one center controller via a transmission line, a plurality of units are received from the defrost controller in response to a time report signal from the center controller. The defrost start signal is sent to the showcase controller to start defrosting the cooler installed in the showcase. , The defrosting start signal from each defrost controller does not collide on the same transmission line, and the communication line is crowded. Occurrence is prevented and communication efficiency is increased.
[0014]
Secondly, the transmission timing of the defrost start signal to each showcase is given priority by uniquely setting the transmission delay time based on the communication address set separately for each defrost controller. The defrost controller that can be transmitted in this way can be determined in units of controllers, uncertainties in communication can be reduced, and communication reliability can be improved.
[0015]
Thirdly, since the defrost controller that performs overall control of the defrost processing of the plurality of showcase controllers is provided in one compressor connected to the plurality of showcases, respectively, the compressor The defrosting of all the plurality of coolers connected to can be started reliably and simultaneously.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a time chart showing an embodiment of a communication control method for a refrigerator-freezer showcase according to the present invention. First, a refrigerator-freezer showcase in which the method of the present invention is implemented will be described. On the other hand, one compressor is not installed in the showcase but installed separately, and the plurality of coolers are connected to the one compressor. Then, a plurality of compressors connected to the plurality of coolers are installed.
[0017]
The present invention is implemented in a refrigerated showcase having such a refrigeration cycle. Shower controllers 4a, 4b, 4c,..., 4n are provided in coolers installed in each showcase, respectively, and compressors (2 In the case of a stand installation), defrost controllers 3a and 3b are provided, respectively.
[0018]
As already described with reference to FIG. 2, the communication control system is provided with showcase controllers 4a, 4b, 4c,..., 4n each having a defrosting means and a communication transmitting / receiving means for each refrigerated showcase. A single defrosting controller 3a or 3b that controls the defrosting process of each showcase controller 4a, 4b, 4c,... 4n is connected to each showcase controller 4a, 4b, 4c,. In addition, a plurality of defrost controllers 3a or 3b, each of which is connected to each group of a plurality of showcase controllers 4a, 4b, 4c,... 4n, are provided, and the plurality of defrost controllers 3a, 3b are provided as one unit. Connected to the center controller 1 by the transmission line 2.
[0019]
In such a communication control system, a plurality of showcase controllers 4a, 4b, 4c,... Are based on communication addresses specifying the defrost controllers 3a, 3b separately set in the defrost controllers 3a, 3b. The transmission delay time t1, t2 for shifting the transmission time of the defrosting start signal to 4n between the defrosting controllers 3a, 3b is calculated, and this time is set in each defrosting controller 3a, 3b.
[0020]
As described above, the defrosting start time is set in the center controller 1 at regular intervals, and when the set time is reached, the time notification signal 5 is simultaneously sent from the center controller 1 to the defrosting controllers 3a and 3b. Entered.
[0021]
The defrost controllers 3a and 3b receive the time notification signal 5, and the defrost start signals are sent to the plurality of showcase controllers 4a, 4b, 4c,... 4n connected to the respective defrost controllers 3a and 3b. 6 and 7 are transmitted. At this time, since the transmission delay times t1 and t2 are set in the defrost controllers 3a and 3b, even if the time notification signal 5 from the center controller 1 is received at the same time, a plurality of showcase controllers 4a, Transmission of the defrosting start signals 6 and 7 to 4b, 4c,..., 4n is shifted by transmission delay times t1 and t2 as shown in FIG.
[0022]
Thereby, after transmission of the defrost start signal 6 from one defrost controller 3a is complete | finished, transmission of the defrost start signal 7 from the next 2nd defrost controller 3b starts. Therefore, even if the transmission timing is uniquely deviated for a certain time and the defrost start signals 6 and 7 from the defrost controllers 3a and 3b are placed on the communication line of the same transmission line 2, the two signals do not collide. In the figure, time t3 is an internal processing time in the defrost controllers 3a and 3b.
[0023]
As a result, the defrosting process can be synchronized, and the defrosting of the plurality of coolers connected to one compressor starts at the same time for each compressor.
[0024]
【The invention's effect】
As described above, the communication control method for the freezer / refrigerated showcase according to the present invention firstly includes a show comprising a defrosting means and a communication transmitting / receiving means for each of the plurality of frozen / refrigerated showcases. Each case controller is provided, and one defrost controller that controls the defrosting of these multiple showcase controllers is connected to each showcase controller via a transmission line, one for each showcase controller group In a communication control method for a refrigerated showcase in which a plurality of defrost controllers connected to each other are provided, and the plurality of defrost controllers are connected to one center controller via a transmission line, a time report signal is received from the center controller. From the defrost controller to multiple showcase controllers, the cooler installed in the showcase When transmitting a defrost start signal for starting frost, the defrost start signal from each defrost controller may collide on the same transmission line by shifting the transmission timing to each showcase controller by a certain time. In addition, the occurrence of a time zone in which the communication line is congested is prevented, and the unused time zone during which communication is not performed is reduced, the communication state can be leveled, and the communication efficiency is increased.
[0025]
Secondly, the transmission timing of the defrost start signal to each showcase is given priority by uniquely setting the transmission delay time based on the communication address set separately for each defrost controller. The defrost controller that can be transmitted in this way can be determined in units of controllers, uncertainties in communication can be reduced, and communication reliability can be improved.
[0026]
3rdly, since the defrost controller which carries out overall control of the defrosting process of several showcase controllers is provided in the one compressor which the cooler of each installation connects to several showcases, The defrosting process of the showcase controller can be synchronized, and the defrosting of all the plurality of coolers connected to the compressor can be started reliably at the same time.
[Brief description of the drawings]
FIG. 1 is a time chart showing an embodiment of a communication control method for a refrigerated showcase according to the present invention.
FIG. 2 is a control block diagram showing an embodiment of a communication control method for a refrigerated showcase according to the present invention.
FIG. 3 is a time chart showing a communication control method of a conventional refrigerated showcase.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Center controller 2 ... Transmission line 3a, 3b ... Defrost controller 4a, 4b, 4c, ... 4n ... Showcase controller 5 ... Time report signal 6, 7 ... Defrost start signal

Claims (1)

A showcase controller provided with a defrosting means and a communication transmission / reception means is provided for each of the plurality of freezer / refrigerated showcases, and the defrosting process of the plurality of showcase controllers is integrated and controlled 1 A defrost controller is connected to each showcase controller via a transmission line, and a plurality of defrost controllers are connected to each showcase controller group, and one defrost controller is installed. connected by transmission lines to the central controller, further into a plurality of showcases controller from the defrosting controller receives the time message signal from the center controller, defrosting for initiating defrost of the cooler installed on the showcase when you send a start signal, freezing cold to shift the timing of transmission to each showcase by a certain time In the communication control method of the showcase, the transmission timing of the defrosting start signal to each showcase, a staggering the transmission delay time by setting time based on the communication address that is set individually for each defrosting controller A communication control method for a freezer / refrigerated showcase.

Images