JP2005126156A - Group control system of elevator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a group control system of an elevator having unit control devices 3a and 3b for elevator units capable of reducing the load of the group managerial control and assuring interchangeability even with the case where no group managerial control is conducted. <P>SOLUTION: Each unit control device 3a is equipped with a control part 3a1 to perform an operational control of the elevator and a communication part 3a2 to tranceive the information to/from a group managerial control device 2 and the unit control devices 3b. Owing to the arrangement in which the control part 3a1 and the communication part 3a2 are provided separately, the unit control device 3a can disperse the load of the control processing. Further the transceiving control functions of the information to/from the group managerial control device 2 and the other unit control devices 3b are congested in the communication part 3a2, and it is possible to work easily with a one-car system whereto no group control is conducted by introducing such a constitution as to remove only the communication part 3a2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an elevator group management system including a plurality of each vehicle control device that controls each elevator unit and a group management control device that controls the elevator group. The present invention relates to an elevator group management system that performs communication control of input / output information with the apparatus and the group management control apparatus.

  In a conventional elevator group management system, a hall call input / output device that controls the input / output of a hall call on each floor and an operation control device are connected by a single transmission line for each car system. There is one in which the group management control device is connected by a separate transmission line so that the group management system can be easily constructed with high reliability (for example, see Patent Document 1).

  In such a group management system, each operation control device is a part that controls transmission / reception between cars and transmission / reception between hall call input / output devices, a car transmission control device, a group management control device, And a group control transmission control device, which is a part for controlling transmission / reception of the above-described signals. Further, both of these transmission control devices have a configuration in which they are centrally managed by an operation control microcomputer.

  This eliminates the need to drastically replace the system in order to change multiple one-car systems into a group management system during renovation work, and can reduce enormous costs and time labor required for renovation. .

  In addition, I / O that connects a plurality of vehicle control devices that control each elevator unit and a group management control device via a hub, which is a bus-type communication path, to connect landing equipment, expansion equipment, and external equipment There is a group management system in which devices are provided in a hub (see, for example, Patent Document 2).

  In such a group management system, input / output information of expansion devices, external devices, and landing devices of each unit is shared by each of the plurality of vehicle control devices and the group management control device. As a result, even when the group management control device is stopped, each of the plurality of control devices can respond to the landing equipment, and the deterioration of the service of the entire system can be minimized.

JP 2001-335249 A (first page, FIG. 1) Japanese Patent Laid-Open No. 2002-3108 (page 4, FIG. 1)

  However, the prior art has the following problems. In the configuration in which the operation control microcomputer is centrally managed as described above, the operation control microcomputer must perform operation control for the elevator and also perform operation control for group management. Therefore, when an external device, an expansion device, or the like is additionally added to the elevator, the load on the operation control microcomputer further increases. Furthermore, for a one-car system that does not need to perform group management control, the operation control microcomputer used in the multi-car system that needs to perform group management control cannot be shared as it is, and standardization as an elevator system cannot be performed. There was a problem.

  Further, in the configuration in which the input / output device is provided in the hub, there is a problem that the wiring of the landing equipment, the extension equipment, and the external equipment is concentrated on the hub. Further, for one car system, the landing equipment, the extension equipment, and the external equipment are connected to the respective control devices, so that the connection configuration is completely different from that for the multi-car system. As a result, the control of input / output information is also incompatible between the one-car system and the multi-car system, and there is a problem that dedicated control is required for each and the standardization as an elevator system cannot be performed.

  The present invention has been made to solve the above-described problems, and is compatible with a case where the load of group management control is reduced in each elevator control device of each elevator and the group management control is not performed. An object is to obtain an elevator group management system having a characteristic configuration.

  An elevator group management system according to the present invention includes a group management control device that performs group management control of a plurality of elevators, a plurality of vehicle control devices that control each elevator unit, a group management control device, and a plurality of vehicle control systems. Elevator group management control system provided with a hub that connects to a device via a bus-type communication path, and a transmission path that is provided for each elevator unit in order to transmit and receive information between each vehicle control device and landing equipment And each stand control device has a communication unit and a control unit individually connected to the transmission path in order to individually transmit and receive information with the hall device, the communication unit is connected to the hub, Group management information is generated based on the information from the landing equipment and transmitted to the group management control device and other unit control devices of the other units via the hub, and the group management control device is based on the group management information of each unit. Each generated system The command and the group management information generated by the control devices of other units are received via the hub, information necessary for operation control is generated and transferred to the control unit, and the control unit is transferred from the communication unit. The operation control of the elevator is performed based on information necessary for the operation control and information from the landing equipment.

  According to the present invention, in each unit control device of each elevator unit, a communication unit that transmits and receives information to and from the group management control unit and other unit control units, and a control unit that performs operation control of each unit of the elevator Can be obtained separately, and an elevator group management system having a compatible structure can be obtained even when the group management control is not performed.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. In the first embodiment of the present invention, a case where group management control is performed on two elevators of No. a and No. b will be described. FIG. 1 is a configuration diagram of an elevator group management system according to Embodiment 1 of the present invention. The suffixes a and b of the code correspond to the elevator machine.

  As shown in FIG. 1, a group management control device 2 that performs group management control of a plurality of elevators and respective vehicle control devices 3 a and 3 b that respectively control each elevator unit are connected via a hub 1. Here, the hub 1 connects the group management control device 2 and the plurality of vehicle control devices 3a and 3b by a bus-type communication path, and serves as a communication path for mutual information.

  Further, each of the vehicle control devices 3a and 3b is connected to landing devices 4a and 4b such as call buttons installed at the landing via transmission lines 5a and 5b, respectively. Each table control device 3a, 3b has the same function, and the contents common to both are described below using each table control device 3a.

  Each vehicle control device 3a inputs and outputs information to and from the control unit 3a1 that controls the operation of the elevator, the group management control device 2 and the communication device 3a2 that transmits and receives information to and from each vehicle control device 3b, and the expansion device 6. An expansion device input / output unit 3a3 and an external device input / output unit 3a4 for inputting / outputting information to / from the external device 8 are provided. The hall device 4a is connected to the control unit 3a1 and the communication unit 3a2 via the transmission path 5a. By adopting such a configuration, the control unit 3a1 and the communication unit 3a2 can individually transmit and receive information to and from the hall device 4a.

  The control unit 3a1 includes a CPU, a serial input / output unit (hereinafter referred to as SIO), and a control circuit, and is controlled by the CPU. The CPU of the control unit 3a1 is connected to the transmission path 5a via the SIO, and transmits / receives information to / from the hall device 4a. Further, the CPU of the control unit 3a1 controls the operation of the elevator by controlling the control circuit. Although not shown, the elevator control mechanism is connected to the control circuit.

  On the other hand, the communication unit 3a2 includes a microcomputer (hereinafter referred to as a microcomputer), an SIO, and an Ether Controller, and is controlled by the microcomputer. Similarly to the control unit 3a1, the microcomputer of the communication unit 3a2 is connected to the transmission path 5a via the SIO, and transmits / receives information to / from the landing device 4a. Further, the microcomputer of the communication unit 3a2 is connected to the hub 1 via the Ether Controller, and transmits / receives information to / from the group management control device 2 and each of the vehicle control devices 3b. Further, the microcomputer of the communication unit 3a2 is directly connected to the CPU of the control unit 3a1 so that the information received from the group management control device 2 and each of the control devices 3b can be transferred to the control unit 3a1 via the Ether Controller and the hub 1. ing.

  The microcomputer of the communication unit 3a2 can directly receive information from the hall device 4a via the SIO. When the microcomputer of the communication unit 3a2 determines that the received information is information that the group management control device 2 should manage, that is, group management information, the microcomputer transmits the group management information via the Ether Controller. . As a result, the group management control device 2 and each vehicle control device 3b can receive the group management information transmitted from each vehicle control device 3a via the hub 1.

  The group management control device 2 generates each vehicle control command to each vehicle control device 3a, 3b based on the respective group management information received from each vehicle control device 3a, 3b via the hub 1, and the hub 1 Is transmitted to each of the control devices 3a and 3b. The communication unit 3a2 of each table control device 3a can receive each table control command from the group management control device 2 and group management information from each table control device 3b via the hub 1 and the Ether Controller.

  By adopting such a configuration, the control unit 3a1 receives information from the landing device 4a via the transmission path 5a, and also receives each vehicle control command from the group management control device 2 and each vehicle control device 3b. The group management information can be received via the microcomputer of the communication unit 3a2. The control unit 3a1 can control the operation of the elevator by controlling the control circuit based on these reception results, and can perform the optimal operation control in consideration of the information received via the hub 1.

  Furthermore, in the elevator group management system according to Embodiment 1 of the present invention, the extension device 6 can be connected as follows. For example, when permitting a specific user to use an elevator, a fingerprint reader or a card reader used to read the personal identification information of the specific user belongs to the expansion device 6. Each of the control devices 3a can identify the user by receiving this personal identification information as information from the extension device.

  For the connection of the expansion device 6, an expansion device input / output unit 3a3 including a parallel input / output unit (hereinafter referred to as PIO), a microcomputer, and an SIO is used. The expansion device 6 is connected to the PIO via the parallel communication path 7 and is controlled by the microcomputer. Furthermore, it is connected to the transmission path 5a by SIO, so that the control unit 3a1 and the communication unit 3a2 of each control device 3a can transmit / receive information to / from the extension device 6.

  In addition, as with the extended device 6, an external device 8 can be connected. For example, a device outside an elevator group corresponding to a building management system belongs to this external device. When the elevator is guided to the entrance floor in conjunction with the unlocking of the door at the entrance of the building, each control device 3a receives the unlocking information of this door as information from an external device, The same control as when the hall call button is pressed can be performed.

  For connection of the external device 8, an external device input / output unit 3a4 including an I / O, a microcomputer, and an SIO is used. The external device 8 is connected to the I / O via the external communication path 9 and is controlled by the microcomputer. Furthermore, it is connected to the transmission path 5a by SIO, whereby the control unit 3a1 and the communication unit 3a2 of each control device 3a can transmit and receive information to and from the external device 8.

  By having such a connection, the control unit 3a1 and the communication unit 3a2 in each of the control devices 3a can transmit / receive information to / from the landing device 4a, the expansion device 6, and the external device 8 through the transmission path 5a. . The control unit 3a1 can receive information from the extension device 6 and the external device 8 in the same manner as information from the landing device 4a, and can perform operation control based on the received information. Further, the communication unit 3a2 can transmit not only information from the landing device 4a but also group management information in consideration of information from the extension device 6 and the external device 8. As a result, the group management control device 2 and each stand control device 3b can also receive information from the extension device 6 and the external device 8 connected to each stand control device 3a.

  By adopting the above configuration, the control processing load can be distributed between the control unit 3a1 and the communication unit 3a2. That is, the operation control of the elevator is performed by the control unit 3a1, and the transmission / reception control of information with the group management control device 2 and each vehicle control device 3b is performed by the communication unit 3a2. Thereby, even if it removes communication part 3a2 also about 1 car system which does not perform group management, the composition of each stand control device 3a can be made the same, and standardization as an elevator system is attained.

  Next, the flow of processing based on specific information will be described. FIG. 2 is a flowchart showing a series of processing of information via the transmission path and the hub. Information from the three types of hall device 4a, expansion device 6, and external device 8 is transmitted to the transmission path 5a. When a hall call button is pressed from the hall device 4a, each vehicle control device associated therewith is transmitted. The description will focus on the processes 3a and 3b.

  From the hall device 4a, hall call button information is set by pressing the hall call button (S201), and is transmitted to the transmission path 5a. Extended device input / output information is set from the extended device 6 (S202), and is transmitted to the transmission path 5a via the extended device input / output unit 3a3 (S203). Also, external device input / output information is set from the external device 8 (S204) and transmitted to the transmission line 5a via the external device input / output unit 3a4 (S205).

  These pieces of information are individually received by the control unit 3a1 and the communication unit 3a2 of each stand control device 3a via the transmission path 5a. First, the process of the control unit 3a1 will be described. In processing the information received via the transmission path 5a, the control unit 3a1 confirms whether or not the group management control device 2 is normal (S206).

  Here, each of the control devices 3a and 3b can determine whether or not the group management control device 2 is normal as follows. For example, whether or not certain communication information is transmitted from the communication units 3a2 and 3b2 of the control devices 3a and 3b to the group management control device 2 via the hub 1 and a response to the information can be received within a predetermined time. Check regularly. As a result, the communication units 3a2 and 3b2 of the control devices 3a and 3b can determine the state of the group management control device 2. Further, the communication units 3a2 and 3b2 periodically transfer information on the state of the group management control device 2 to the control units 3a1 and 3b1, so that the control units 3a1 and 3b1 also have the status of the group management control device 2. Can be grasped.

  When the group management control device 2 is normal, the control unit 3a1 determines whether the received information is each unit management information managed by each unit control device 3a or the group management managed by the group management control device 2. It is determined whether it is information (S207).

  Here, each vehicle management information managed by each vehicle control device 3a is related to each vehicle control device other than each vehicle control device 3a (ie, equivalent to each vehicle control device 3b in the first embodiment). Information that does not need to be done. For example, information on a key switch provided at an elevator hall and for switching between operation / stop of the elevator is directly taken into the control unit 3a1 and belongs to each vehicle management information. Further, the group management information managed by the group management control device 2 is information related to a plurality of individual control devices. For example, the hall call button information is information that should be group-managed in elevators of other cars, and belongs to the group management information.

  If it is determined in step S207 that the vehicle management information is included, the control unit 3a1 performs elevator operation control based on the vehicle management information (S208). On the other hand, when it is determined in step S207 that the information is not management information for each unit, the control unit 3a1 discards this information (S209). The discarded information is processed as group management information by the communication unit 3a2, and details will be described later.

  If the group management control device 2 is not normal in the previous step number S206, the control unit 3a1 controls the operation of the elevator using the step number S208 based on the information received via the transmission path 5a. That is, when the group management control device 2 is not normal, the information received via the transmission path 5a of the No. a machine is the management information of each unit or the group management information, but the control unit 3a1 uses the transmission path 5a. Operation control is performed directly according to all the information received via the network.

  Next, processing of the communication unit 3a2 will be described. The communication unit 3a2 determines whether the information received via the transmission line 5a is the group management information managed by the group management control device 2 or the respective unit management information managed by each of the table control devices 3a (S210). ).

  If it is determined in step S210 that the information is group management information, the communication unit 3a2 transmits the group management information to the hub 1 (S211). This transferred information corresponds to the information discarded in step S209 described above. As described above, the group management information received via the transmission path 5a is transmitted to the hub 1 in step number S211 even when the group management control device 2 is not normal. Thereby, each stand control device 3b can receive the group management information from each stand control device 3a via the hub 1 even when the group management control device 2 is not normal.

  On the other hand, when it is determined in step number S210 that the information is not group management information (that is, each vehicle management information), the communication unit 3a2 discards this information (S212). The discarded information corresponds to the information that is determined as the individual vehicle management information by the control unit 3a1 at step number S207 and is used for operation control at step number S208.

  Next, the hub 1 to which the group management information has been transmitted in step number S211 transmits the group management information to all devices connected to the hub 1 (that is, the group management control device 2 and each unit in the first embodiment). It serves as a communication path for transmission to the control device 3b). The group management control device 2 performs group management control based on the group management information received via the hub 1, generates each vehicle control command for each vehicle control device, and transmits the command to the hub 1.

  Moreover, the communication part 3b2 of each stand control apparatus 3b performs the following processes based on each stand control command received from the group management control apparatus 2 and the group management information received from each stand control apparatus 3a. First, the communication unit 3b2 confirms whether or not the group management control device 2 is normal (S214). If the group management control device 2 is normal, the communication unit 3b2 determines whether the received information is a control command for each unit (S215). When it is determined that the control command is for each vehicle, the communication unit 3b2 transfers this information to the control unit 3b1 (S216).

  If it is determined in step S215 that the control command is not for each vehicle (that is, group management information), the communication unit 3b2 discards this information (S217). When the group management control device 2 is normal, the communication unit 3b2 does not adopt the group management information from each table control device 3a, but follows each table control command from the group management control device 2.

  If the group management control device 2 is not normal in the previous step number S214, the communication unit 3b2 transfers the group management information received from each of the vehicle control devices 3a to the control unit 3b1 as it is (S216). Originally, the group management information received from each unit control device 3a should be discarded, and is the content to be processed based on each unit control command received from the group management control device 2. However, when the group management control device 2 is not normal, the communication unit 3b2 does not receive the control command for each unit from the group management control device 2.

  Therefore, in such a case, the communication unit 3b2 transmits / receives the group management information to / from each unit control device 3a by transmitting / receiving the group management information to / from each unit control device without passing through the group management control device 2. It can be directly handled as a command to each stand control device 3b. By performing such processing, even when the group management control device 2 is not normal, each unit control device can perform operation control in consideration of information from each other unit control device. The control unit 3b1 controls the operation of the elevator according to the information transferred from the communication unit 3b2 at step number S216 (S218).

  In FIG. 2, a series of flows has been described focusing on the processing of information from the hall device 4a. Next, a series of processing based on each vehicle management information from the transmission path 5a, group management information from the hub 1, and each vehicle control command will be described, focusing on operation control in each vehicle control device 3a. FIG. 3 is a flowchart showing a series of processing of information received by each of the control devices 3a. Each stand control device 3a performs operation control based on information received via its own transmission path 5a and information from the group management control device 2 or each stand control device 3b received via the hub 1. . Note that the information received via the transmission path 5a is the same as step numbers S201 to S205 in FIG. 2, and the same step numbers are given and description thereof is omitted.

  The group management control device 2 generates each vehicle control command based on the group management information from each vehicle control device 3a, 3b and transmits it to the hub 1 (S301). Moreover, the communication part 3b2 of each stand control apparatus 3b transmits the group management information as an elevator of No. b machine to the hub 1 (S302). The communication unit 3a2 of each table control device 3a performs the following processing on the information received via the hub 1, that is, each table control command from the group management control device 2 or group management information from each table control device 3b. Execute.

  First, the communication unit 3a2 confirms whether or not the group management control device 2 is normal (S303). When the group management control device 2 is normal, the communication unit 3a2 determines whether or not the received information is a control command for each unit (S304). When it is determined that the control command is for each unit, the communication unit 3a2 transfers this information to the control unit 3a1 (S305). If it is determined in step S304 that the control command is not for each vehicle (that is, group management information), the communication unit 3a2 discards this information (S306).

  If the group management control device 2 is not normal at the previous step number S303, the communication unit 3a2 transfers the group management information received from each of the control devices 3b to the control unit 3a1 as it is (S305). Originally, the group management information received from each unit control device 3b should be discarded, and is the content to be processed based on each unit control command received from the group management control device 2. However, when the group management control device 2 is not normal, the communication unit 3a2 does not receive the control command for each unit from the group management control device 2.

  Therefore, in such a case, the communication unit 3a2 transmits / receives the group management information to / from each unit control device 3b without transmitting the group management control device 2 between each unit control device. It can be directly handled as a command to each control device 3a. By performing such processing, even when the group management control device 2 is not normal, each unit control device can perform operation control in consideration of information from each other unit control device.

  Next, processing of the control unit 3a1 will be described. In processing the information received via the transmission path 5a, the control unit 3a1 confirms whether or not the group management control device 2 is normal (S307). When the group management control device 2 is normal, the control unit 3a1 determines whether the information received via the transmission path 5a is the management information managed by each control device 3a or the group management control device 2. It is determined whether the group management information is managed (S308).

  If it is determined in step S308 that the management information is for each vehicle, the control unit 3a1 controls the operation of the elevator based on the management information for each vehicle (S309). On the other hand, if it is determined in step S308 that the information is not management information for each vehicle (that is, group management information), the control unit 3a1 discards this information (S310).

  When the group management control device 2 is not normal in the previous step number S307, the control unit 3a1 controls the operation of the elevator by the step number S309 based on the information received via the transmission path 5a. That is, when the group management control device 2 is not normal, the information received via the transmission path 5a of the No. a machine is the management information of each unit or the group management information, but the control unit 3a1 uses the transmission path 5a. Operation control is performed directly according to all the information received via the network.

  Furthermore, the control unit 3a1 also performs elevator operation control based on the information transferred from the communication unit 3a2 in the previous step number S305 (S309). In this way, the control unit 3a1 can execute the operation control of the elevator based on the information received via the transmission path 5a and the information transferred from the communication unit 3a2 via the hub 1. When the group management control device 2 is not normal, handling of the group management information from each other control device is ruled in advance so that the control unit 3a1 can respond to the normal / abnormal state of the group management control device 2. Therefore, the optimal operation control of the elevator can be realized.

  According to the first embodiment, each control device can disperse the load of control processing by providing the control unit and the communication unit individually. Furthermore, the transmission / reception control function of information with the group management control device and each other control device is integrated in the communication unit, and even for a one-car system that does not perform group management, only the communication unit is removed. Therefore, it can be easily handled. Furthermore, even when the group management control device is in an abnormal state, each of the vehicle control devices can execute the optimum operation control of the elevator based on the result of transmission and reception of information between the vehicle control devices. Furthermore, an external device or an expansion device can be connected to each control device, and the system can be easily expanded.

  In the first embodiment, the case where each of the control devices 3a and 3b determines the normal state of the group management control device 2 has been described. However, the same method is applied to other units connected to the hub 1. It can also be applied between devices. For example, each unit control device 3a periodically transmits certain information to each unit control device 3b via the hub 1, and periodically checks whether or not a response to the specific information can be received within a predetermined time. Thus, each of the control devices 3a can determine the normal / abnormal state of each of the control devices 3b. In addition, the group management control device 2 periodically transmits certain information to each of the vehicle control devices 3a via the hub 1, and periodically checks whether or not a response to the specific information can be received within a predetermined time. Thus, the group management control device 2 can determine the normal / abnormal state of each of the control devices 3a.

  By confirming the normal / abnormal state between the devices, each device can determine that the information from the device determined not to be in the normal state is invalid and discard it. Further, when it is determined that a plurality of devices are not in a normal state, each device can also estimate a failure of the hub 1, that is, a failure of the communication path.

It is a block diagram of the elevator group management system which concerns on Embodiment 1 of this invention. It is the flowchart which showed a series of processes of the information via a transmission line and a hub. It is the flowchart which showed a series of processes of the information which each stand control apparatus received.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub, 2 group management control apparatus, 3a, 3b Each control apparatus, 3a1, 3b1 Control part, 3a2, 3b2 Communication part, 3a3 Expansion apparatus input / output part, 3a4 External apparatus input / output part, 4a, 4b Landing apparatus, 5a 5b Transmission path, 6 expansion device, 7 parallel communication path, 8 external device, 9 external communication path.

Claims (4)

A group management control device for group management control of a plurality of elevators;
A plurality of control devices for controlling each elevator unit,
A hub that connects the group management control device and each of the plurality of control devices with a bus-type communication path;
In an elevator group management control system comprising: a transmission path provided for each elevator unit in order to transmit and receive information between each vehicle control device and a landing device;
Each of the vehicle control devices has a communication unit and a control unit individually connected to the transmission path in order to individually transmit and receive information to and from the hall device,
The communication unit is connected to the hub, generates group management information based on information from the landing equipment, and transmits the group management control device and other unit control devices of the other unit through the hub, The group management control device receives each unit control command generated based on the group management information of each unit and the group management information generated by each unit control unit of the other unit via the hub, for operation control. Generate the necessary information and transfer it to the control unit,
The said control part performs operation control of an elevator based on the information required for the operation control transferred from the said communication part, and the information from the said landing apparatus. The elevator group management system characterized by the above-mentioned. In the elevator group management system according to claim 1,
The communication unit determines whether the group management control device is in a normal state by transmitting specific information to the group management control device and receiving a response to the specific information, and controls the state. When the group management control device is not in a normal state, the group management information from each of the other unit control devices is transferred to the control unit, and the group management control device is in a normal state. If there is, discard the group management information from each unit control device of the other unit and transfer each unit control command from the group management control device to the control unit,
The control unit performs operation control of the elevator based on information from the landing device, the group management information from the communication unit, the individual vehicle control commands, and the state of the group management control device. Elevator group management system. In the elevator group management system according to claim 1 or 2,
Each of the vehicle control devices further includes an expansion device input / output unit for transmitting and receiving information to and from the expansion device at the hall,
The expansion device input / output unit is connected to the communication unit and the control unit via the transmission path. In the elevator group management system according to any one of claims 1 to 3,
Each of the vehicle control devices further includes an external device input / output unit for transmitting and receiving information to and from an external device at the hall,
The external device input / output unit is connected to the communication unit and the control unit via the transmission path.

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