JPH10108278A - Communication control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically change a self communication specification in accordance with system configuration by adopting the specification as a slave in a first system when the control signal is received within a fixed period at the time of power supply and adopting it as a master in the second system when the signal is not received so as to respectively execute an operation by means of the specification. SOLUTION: A representative control terminal equipment 1a which is set as a representative judges whether or not a self transmitting/receiving cicuit receives the control signal from a control unit 7 at first. When it is received, the self communication specification is fixed as the slave and a communication control system is operated as the first system. In the meantime, when the transmitting/receiving circuit judges that the control signal is not received and also a non-reception time elapses for a fixed time, it is judged that the control unit 7 for executing master communication does not exist in the system so that it is decided that the terminal equipment itself is the master communication specification for controlling the operations of the other control terminal equipment 1b-1d and the system is operated as the second system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control system in which a plurality of control terminals for performing the same control on the same type of load are connected in a multi-drop manner by a single communication line to operate the control terminals. Things.

[0002]

2. Description of the Related Art In general, when communication is to be performed between control terminals in a multi-drop wiring for connecting a plurality of control terminals on the same communication line, an address which is an address of a transmission destination is included in communication data. An identification number called is required. The address is usually the system's default state,
It is artificially set to each control terminal by an address setting switch or the like. In a simple communication control system, as shown in JP-A-5-227573, when a system is powered on, a specific representative control terminal having a representative function operates and monitors itself. It is often configured as a system without address setting by determining whether or not is connected and determining its own communication specifications in the system.

In such a communication control system, when a control unit for performing master communication is connected to one representative control terminal, the control unit transmits and receives control signals to thereby control the representative control terminal. Is operated and monitored, and the other control terminals are operated from the control unit according to the communication specifications of a slave that only receives a control signal from the control unit via a communication line. Also, when the external control unit is connected by another communication line and sends an operation instruction signal to one representative control terminal, the representative control terminal performs the same operation as its own to other control terminals. The operation is performed according to the communication specification of the master that performs the communication.

[0004]

In the communication control system described above, when the power of the system is turned on, the representative control terminal determines whether or not a control unit for operating and monitoring itself is connected. If it is determined that it has not been performed and its own communication specification in the communication control system is determined to be master,
When the control unit performing the master communication is retrofitted, the representative control terminal has no means for returning a response signal to the control signal from the retrofitted control unit, and the There is a problem that a communication error occurs due to the collision of the signals. In such a case, even if it is troublesome, the power must be turned on again to change the communication specifications of the representative control terminal.

[0005] Regarding the above-mentioned signal collision, Japanese Patent Laid-Open Publication No.
Japanese Patent Application Publication No. 145559 discloses a technique for processing data collision on a line in a system in which a center device and a plurality of terminals are connected via a multi-drop line. In this method, priorities are set in advance for communication, and when data collision occurs on a line, a communication having a higher priority acquires a transmission right. However, this technique prioritizes communication, and the control unit and the representative control terminal in the above-described communication control system in which the representative control terminal operates according to the master communication specification or operates according to the slave communication specification. It cannot solve the problem caused by the signal collision between the two.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a multi-drop communicable connection via a communication line so that the same load can be applied to the same load. A specific representative control terminal among a plurality of control terminals that controls the communication control system has a function of automatically changing its own communication specifications according to the system configuration without turning on the system power again. And to improve the function of the communication control system for changing the communication specifications.

[0007]

According to a first aspect of the present invention, there is provided a transmission / reception circuit which is communicably connected by a first communication line in a multi-drop manner.
Among a plurality of control terminals that perform the same control on the load of the same form, one specific representative control terminal set with a representative function is connected on a first communication line. The control unit that performs master communication transmits and receives control signals, thereby operating and monitoring the representative control terminal, and the other control terminals use the first communication line for control signals from the control unit. A first system operated by the control unit by performing only reception via the external control unit, and an external control unit connected by a second communication line of another system to one specific representative control terminal are instructed to operate. The representative control terminal transmits a control signal for causing the other control terminal connected to the first communication line to perform the same operation as that of the other control terminal. The communication control system comprising a second system for only reception of the control signal,
When a representative control terminal receives a control signal from a control unit that performs master communication within a certain period of time when the power is turned on, the first system operates according to the communication specification as a slave, and if not, the second system operates. If the control unit that performs the master communication is installed afterwards while operating with this master communication specification, the replacement is detected and the first system is changed to the communication specification as a slave. A means for providing a means for performing the above is adopted.

According to a second aspect of the present invention, a control unit for performing master communication in the means according to the first aspect is retrofitted to the first communication line. During the transmission of the control signal in a fixed cycle for causing the other connected control terminal to perform the same operation as the self, the control signal from the control unit is received during the reception permission period except for during transmission. And a means for detecting when the reception processing is normally completed.

According to a third aspect of the present invention, a control unit for performing master communication in the means according to the first aspect is retrofitted to the first control line by a representative control terminal. While transmitting a control signal at a fixed period to cause another connected control terminal to perform the same operation as its own, collision detection means capable of receiving its own transmission signal at the same timing, and the same timing as the transmission signal Means for detecting by a signal comparing means for comparing the received signal with the received signal.

[0010]

FIG. 1 is a physical configuration diagram of a communication control system showing an embodiment of the present invention. This communication control system includes a plurality of control terminals 1 communicably connected in a multi-drop manner by a first communication line 1 that performs the same control on loads of the same form (air conditioning ventilation device and the like).
a, 1b, 1c and 1d. Each of the control terminals 1a, 1b, 1c, and 1d includes a transmission / reception circuit 2 including a collision detection unit for communication connected to the first communication line 1 and a central processing unit C as shown in FIG.
It includes a PU 3, a representative right setting switch 4, and a receiving circuit 6 that can be connected to a second communication line 5 of a different system from the first communication line 1. In one of the control terminals 1a, 1b, 1c, 1d, the above-mentioned representative right setting switch 4 is turned on, and in the other control terminals, the representative right setting switch 4 is turned off.
F The control terminal 1a whose representative right setting switch 4 is set to ON is the other control terminal 1b, 1c, 1
It is positioned as a representative control terminal 1a having a function representative of d.

A control unit 7 for performing master communication with the representative control terminal 1a and operating and monitoring the representative control terminal 1a is connected to the first communication line 1 in FIG.
And a second communication line 5 of a different system from the first communication line 1 to the representative control terminal 1a as shown in FIG.
The external control unit 8 connected by the above transmits an operation instruction signal to the representative control terminal 1a, and functions in any of the second systems in which the representative control terminal 1a operates according to the master communication specification.

In the first system, the control unit 7 connected to the first communication line 1 performs master communication with the representative control terminal 1a as shown in the logical configuration of FIG. , The operation and monitoring of the representative control terminal 1a are performed. The other control terminals 1b, 1c, 1d are operated from the control unit 7 by only receiving the control signal from the control unit 7 via the first communication line 1. Therefore, the representative control terminal 1a and the other control terminals 1b, 1c and 1d operate as slaves with respect to the control unit 7 performing the master communication, and the representative control terminal 1a operates according to the slave communication specification. The control unit 7 allows the user to start and stop the system and to perform control unique to the device.
It polls communication with respect to each control terminal 1a, 1b, 1c, 1d.

In the second system, an external control unit 8 connected to the representative control terminal 1a by a second communication line 5 of another system transmits an operation instruction signal to the representative control terminal 1a as shown in FIG. The representative control terminal 1a is connected to the other control terminals 1b, 1 connected to the first communication line 1.
A control signal for causing c and 1d to perform the same operation as itself is transmitted, and the other control terminals 1b, 1c and 1d receive only the control signal as slaves. That is, in the second system, the representative control terminal 1a operates according to the master communication specification. The master indicates a unit which independently transmits a control signal to each of the control terminals 1b, 1c and 1d, and the slave receives a control signal from the master and, if necessary, responds to the control signal. Is indicated.

A mixed system of the control unit 7 and the external control unit 8 is also treated as a first system. FIG. 6 shows a physical configuration diagram and FIG. 7 shows a logical configuration diagram. As shown in FIG. 7, the control unit 7 and each of the control terminals 1a, 1b, 1c, 1d communicate with each other, but actually communicate with the control unit 7 in the control terminals 1a, 1b, 1c, 1d. Only the representative control terminal 1a sends a reply, and the other control terminals 1b, 1c,
1d is a representative control terminal 1a from the control unit 7.
Only receive the signal transmitted to. The representative control terminal 1a once transmits an operation instruction signal from the external control unit 8 connected by the second communication line 5 to the control unit 7, and follows the operation request from the control unit 7. Therefore, it is the control unit 7 that has the communication master function, and the representative control terminal 1a.
The other control terminals 1b, 1c, 1d are also slaves.

The CPU 3 of the representative control terminal 1a determines whether to adopt the communication specifications by the first system or the second system by turning on the power of the system in accordance with the procedure shown in the flowchart of FIG. decide.
That is, when the representative right setting switch 4 is turned on and the representative control terminal 1a is set as the representative, the system first turns on the transmitting / receiving circuit 2 from the control unit 7 in # 101 of FIG. It is determined whether a control signal has been received. If the control signal is received in # 101, it is determined that the control unit 7 for performing the master communication exists, and the process proceeds to # 102, and
At 102, its own communication specification is fixed as a slave. As a result, the communication control system operates on the first system.

When it is determined in step # 101 that the transmission / reception circuit 2 does not receive the control signal, it is determined in step # 103 whether or not the control signal has not been received for a predetermined time.
If the predetermined time has not elapsed in # 103, the process returns to # 101, and if it has elapsed, the process of # 104 is executed. # 10
In 4, it is determined that there is no control unit 7 for performing master communication in the system, and it is determined that the control unit 7 is a communication specification as a master for controlling the operations of the other control terminals 1 b, 1 c, 1 d, and the process proceeds to # 105. According to the determination at # 104, this communication control system operates in the second system. At # 105, it is always determined whether or not its own transmission / reception circuit 2 has received a control signal. #
Reference numeral 105 denotes a routine for detecting retrofitting of the control unit 7, and when retrofitting of the control unit 7 is detected in # 105 (in the case of YES in # 105), # 10 is performed.
6 is performed, and no retrofit is detected (# 10
In the case of NO at step 5), the process of # 105 is repeated. # 10
In step 6, a process for setting its own communication specification as a slave is performed. Thus, even when the control unit 7 is retrofitted, the representative control terminal 1a automatically changes its own communication specifications without any troublesome operation such as turning on the power of the system again, and performs a control operation according to the system configuration. Will be performed.

With respect to the processing after # 104 in the flowchart of FIG. 8, a control signal for causing the other control terminals 1b, 1c, 1d connected to the first communication line 1 to perform the same operation as the own terminal is fixed. During transmission in a periodic manner, a method other than a transmission is defined as a reception permission period, and a communication signal is changed when the control signal from the control unit 7 is detected during the reception permission period and reception processing is normally completed.
In the first system, since the representative control terminal 1a is a slave, a receiving program is built in and the burden of additional software can be reduced. That is,
Regarding # 105 for detecting whether or not the control unit 7 shown in FIG. 8 has been retrofitted, the representative control terminal 1a, which has performed the process of operating according to the communication specification as the master in # 104, outputs the output of the external control unit 8. Receiving the operation instruction signal to be transmitted to the other control terminals 1b, 1
The operations of c and 1d are performed, and the process proceeds to # 201 shown in FIG.

In # 201, the other control terminals 1b, 1c,
1d to transmit a control signal instructing the control of 1d,
Proceeds to the process of # 202 in which the reception is permitted. # 202
After the reception of the transmission / reception circuit 2 is permitted in step # 203, it is determined in step # 203 whether a control signal from the control unit 7 has been received. When the control signal is received in # 203, it is determined that the control unit 7 is retrofitted, and the first system operates according to the communication specifications as a slave. When it is determined in step # 203 that no control signal is received, it is determined in step # 204 whether or not a time period during which no control signal is received has elapsed for a predetermined time. If the predetermined time has elapsed in # 204, the process proceeds to # 205, in which the process of setting the transmission / reception circuit 2 to the reception inhibition state is performed in # 205, and the process returns to # 201. If the predetermined time has not elapsed, the process of # 203 is performed. Return to According to the retrofitting detection method of the control unit 7, the retrofitting of the control unit 7 can be detected by the reception control of the transmission / reception circuit 2 of the representative control terminal 1a.

In addition, the retrofitting of the control unit 7 can be detected in the following manner. That is, the other control terminals 1b connected to the first communication line 1,
While the control signal causing the representative control terminal 1a to perform the same operation as its own to 1c and 1d is transmitted in a fixed cycle, the collision detecting means capable of receiving its own transmission signal at the same timing and the same as the transmission signal The detection is performed by a signal comparing unit that compares the reception signal received at the timing. Specifically, the representative control terminal 1a that has performed the process of operating according to the communication specification as the master in # 104 of FIG. 8 receives the operation instruction signal output from the external control unit 8, and receives the other control terminals 1b, Decisions to perform the operations 1c and 1d are made, and # shown in the flowchart of FIG.
It proceeds to the process of 301.

In # 301, the other control terminals 1b,
When the control signals are transmitted to 1c and 1d, reception is performed at the same timing by the transmission / reception circuit 2 having the communication collision detection function, and the process proceeds to # 302. In # 302, the CPU 3 including the comparing means determines whether or not the control signal transmitted by itself and the received signal are the same. If the control signal is the same, the process proceeds to # 303 and the control transmitted by the collision detection function is performed. If it is determined that the signal and the received signal are not the same, it is determined that the control unit 7 has been retrofitted, and processing for operating according to the communication specifications of the first system is performed. If the control signal transmitted by itself and the received signal are the same in # 302,
In # 303, it is determined whether or not the state has passed for a predetermined time. If the fixed time has not elapsed, the process returns to # 303, and if it has elapsed, the process returns to # 301. According to the retrofit detection method of the control unit 7, the function check of the transmission / reception circuit 2 can be performed using the retrofit detection method in the unit inspection at the time of shipment of the communication control system, which is convenient.

[0021]

As is apparent from the above description of the embodiment, according to the first invention, the communication lines are communicably connected in a multi-drop manner, and the same control is performed for the same load. Has a function of automatically changing its own communication specification to a communication specification according to the system configuration without troublesome operation such as restarting the system power supply. A communication control system is obtained.

According to the second and third aspects of the present invention, in addition to the effect of the first aspect, a function relating to a change in communication specifications of the communication control system is improved.

[Brief description of the drawings]

FIG. 1 is a physical configuration diagram showing a first system of a communication control system according to an embodiment with a physical configuration.

FIG. 2 is a configuration diagram illustrating a configuration of a control terminal in the communication control system according to the embodiment;

FIG. 3 is a physical configuration diagram showing a second system of the communication control system according to the embodiment by a physical configuration;

FIG. 4 is a logical configuration diagram showing FIG. 1 as a logical configuration.

FIG. 5 is a logical configuration diagram showing FIG. 3 as a logical configuration.

FIG. 6 is a physical configuration diagram showing, as a physical configuration, another system different from FIG. 4 which is treated as a first system of the communication control system according to the embodiment;

FIG. 7 is a logical configuration diagram showing FIG. 6 as a logical configuration.

FIG. 8 is a flowchart illustrating an operation of the representative control terminal according to the embodiment.

FIG. 9 is a flowchart of a main routine showing the operation of the representative control terminal.

FIG. 10 is a flowchart of a main routine showing the operation of the representative control terminal.

[Explanation of symbols]

1 first communication line, 1a control terminal (representative control terminal), 1b control terminal, 1c control terminal, 1
d control terminal, 2 transmission / reception circuit, 3 CPU,
4 Representative right setting switch, 5 Second communication line, 6
Receiving circuit, 7 control units, 8 external control units.

Claims (3)

[Claims] 1. A plurality of control terminals connected to each other via a first communication line so as to be communicable in a multi-drop format and having a transmission / reception circuit for performing the same control on the same type of load. A control unit, which is connected on the first communication line to a specific representative control terminal set with a function representative of the above and is configured to perform master communication, transmits and receives a control signal. And the other control terminal operates only from the control unit by receiving only the control signal from the control unit via the first communication line. And an external control unit connected to the specific representative control terminal by a second communication line of another system transmits an operation instruction signal to the specific representative control terminal, The representative control terminal transmits a control signal for causing the other control terminal connected to the first communication line to perform the same operation as itself, and the other control terminal only receives the control signal. A second system,
When the representative control terminal receives a control signal from the control unit for performing master communication within a certain period of time when the power is turned on, the first system operates according to the communication specification as a slave in the first system. To work with the communication specifications as a master in the second system,
When the control unit for performing the master communication during the operation according to the master communication specification is retrofitted, a means for detecting the retrofit and changing to the communication specification as a slave in the first system is provided. Communication control system. 2. The communication control system according to claim 1, wherein the representative control terminal determines that the control unit for performing the master communication has been retrofitted, and the other control terminal connected to the first communication line. While transmitting a control signal that causes the machine to perform the same operation as itself at a fixed cycle, the control signal from the above control unit is detected and normally received during the reception permission period except during transmission as a reception permission period. A communication control system for detecting when a process is completed. 3. The communication control system according to claim 1, wherein the representative control terminal determines that the control unit for performing the master communication has been retrofitted, and the other control terminal connected to the first communication line. While transmitting a control signal at a fixed period to cause the machine to perform the same operation as the self, the collision detection means capable of receiving the own transmission signal at the same timing, and a reception signal received at the same timing as the transmission signal. A communication control system characterized by detecting by a signal comparing means for comparing.