JP3496477B2 - Control communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to an FA network.
The present invention relates to a control communication system such as a control system. [0002] 2. Description of the Related Art Generally known FA network systems
As shown in Fig. 1, the system includes a program
A plurality of input / output terminals 2
_-1, 2 _-2, ... 2_-8Are connected by the upper network 11.
Each input / output terminal 2_-1, 2 _-2, ... 2_-8Is the top
I / O devices connected to each under the control of the star
(Control target). Here, an input remote I / O terminal
2_-1Are photoelectric switches, proximity switches, and limit switches.
Switch is connected. Remote I / O terminal for output
2_-3Is connected to a solenoid, a valve or the like. Composite
-Terminal 2_-8Is supported by the communication unit and multiple slaves.
Network, and the slave and master unit
Communication with the network via sub-networks and communication units
It is done. Each slave is, for example, a counter, an A / D
Conversion, D / A conversion, etc.
It can be expanded depending on the system. Each slave is a master
The control target is controlled by a command from the unit 1. Entering
Remote adapter for force 2_-2, Output remote adapter 2
_-FourCan be combined with, for example, a relay terminal
These are also used as communication terminals
And a plurality of slaves constitute a sub-network.
Analog input terminal 2_-FiveIs 1-5V, 4-20m
Convert analog input of A to binary data and import
No. Analog output terminal 2_-6Converts binary data
Convert to 1-5V, 4-20mA, etc. analog and output
I do. Sensor terminal 2_-7Is a photoelectric switch with connector
Switches, proximity switches, etc. are connected. Output signal with sensor
Teaching and external diagnosis are possible. [0004] In this FA network system,
Communication such as a compound terminal with a sub-network under
Unit communicates with the upper master in the upper network
If an error is detected in
Position notification error was notified. [0005] SUMMARY OF THE INVENTION
Conventional network (control communication system)
After the network fails, the subnetwork
Time until the slave station connected to
It takes time and there is an error in the upper network
Even the slave station operates without considering the error
Communication system has a problem with reliability.
Was. In a conventional FA network system,
Exceeds the allowable range (time, number, etc.) for the network
Error occurs, an error message is displayed and the system is
However, in such a system, the system error
Operation does not exceed the allowable range even if
Beyond the permissible range,
It is possible to know that a communication error has occurred. That is,
If the system does not go down, you will not know the error
In a sense, there was a problem with the reliability of the system. The present invention has been made in view of the above problems.
Communication error occurs in the upper network.
In such a case, it is possible to quickly respond to lower-level devices,
System goes down completely due to notification error
Control communication system that can be addressed by the user (operator) before
The purpose is to provide a system. [0008] A control communication system according to the present invention is provided.
The system isWhen the host master and the communication unit are connected and
Configure the network, communication unit and multiple slaves
Is connected to a different subnet network from the higher-level network.
And the slaves have their own control targets.
Connected, and the communication unit
Protocol conversion with the
Is the upper network, communication unit, and subnet
Communicating via workpiece allows command from upper master
The control of the control target is performed more.
Control communication system that can be controlled by local devices
, The communication unit is connected via the upper network
Each time a packet is received from the upper master, a communication error check is performed.
Check the frequency of communication errors in the upper network.
Means to detect and to slave via sub-network
Control of connected control target from control by host master
Switching signal for switching to control by local device
Error output terminal to output, and communication in upper network
When the error frequency exceeds a first predetermined value, an error output terminal
Means for performing communication error processing for outputting a switching signal to the
Communication error frequency in the local network is greater than the first predetermined value
Exceeds the second predetermined value, which is a small number.
Communication means for notifying the communication error of the communication unit.
Output the switching signal to the error output terminal.
Connected to multiple slaves connected to the communication unit
Control of the controlled object from the control by the master
Switching to control by local equipment. In this control communication system,Communication
Unit's communication error processing means switches to the error output terminal.
Output the number of switches connected to the communication unit.
The control of the control target connected to the slave
Is switched from local control to local device control. this
Thereby, the reliability of the system can be ensured. In this control communication system,
The frequency of communication errors in the upper network is lower than the first predetermined value.
Exceeds the second predetermined value, which is a smaller number,
Notified by the notifying means.This allows the operator
No communication error occurred until the system went down
Knows that a significant error has occurred,
Without taking the system down.
Wear. [0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The light will be described in more detail. FIG. 2 shows one embodiment of the present invention.
Block diagram showing a schematic configuration of the form FA network system.
FIG. In FIG. 2, the slave 20 has a plurality of functions.
Slave 20 as part_-1, ......, 20_-FourAnd the communication unit
20_-0And the subnetwork 21
The communication between the slave 20 and the upper communication master 10
Communication is performed on the sub-network 21, the communication unit 20_-0,Up
This is performed via the location network 11. Slave 2
0_-1, 20_-2, ......, 20_-FourIs a counter, A / D conversion
, Which has functions such as D / A conversion
Can be added by the host communication master 10.
Through the I / O interface 22
The control target 23 is controlled. Communication unit 20_-0Is the top FA network
A communication circuit 31 for performing communication in the network 11;
MPU 32 for performing error control, and sub-network 21
A communication circuit 33 for performing communication by the
-An output terminal 35 and a higher-level FA network
11 performs protocol conversion between the subnetwork 21 and the like.
U. The load power supply 24 supplies a power supply voltage to the control target 23.
ing. Communication unit 20 of slave 20_-0Error
The provision of the force terminal 35 is the
It is the most characteristic of the work system. Next, referring to the flowchart shown in FIG.
Embodiment of the communication unit of the FA network system
The operation will be described. Communication unit 20_-0Is the top F
Receives the upper FA packet from the A network 11
(Step ST1). Perform a CRC check for each reception,
If there is a communication error, for example, check the number of
Determines whether a communication error of a fixed number or more has occurred.
(Step ST2), including the case where there is no communication error,
If the communication error has not reached the specified number of times,
Normal processing is performed as a step (step ST3).
The process returns to step ST1 and waits for the next reception. In step ST2, it is determined that there is a communication error.
Output terminal 34, the error output terminal 35
Is turned on (step ST4). This
Output of the load signal of the controlled object 23
Upper-level communication error processing such as cutting off the power supply from the power source 24
I do. The control of the control target 23 is sent to the host
Local PLC of completely different system from that by the master
The control may be switched to the control by FIG. 4 shows an FA network according to another embodiment of the present invention.
1 is a block diagram illustrating a schematic configuration of a network system.
In the FA network system of this embodiment,
Upper, upper communication master 10, upper FA network 11,
Communication unit 20_-0, Slave 20, and control target 23
The basic relationship is not particularly different from that shown in FIG. Ma
The communication unit 20_-0Is the communication circuit 31, MPU3
2. In having the communication circuit 33 and the output circuit 34,
This is not different from that shown in FIG. But this implementation
Communication unit 20_-0Indicates output terminals 36 and 37
It is characterized by having an element 38. The output terminal 36
If a communication error occurs a predetermined number of times (for example, 200 times),
This terminal outputs a communication abnormal signal, and is controlled by this signal.
The output terminal 35 of FIG.
Equivalent to. The output terminal 37 outputs the communication error
A predetermined number of times smaller than the usual number of times (eg, 200 times)
(Example: 100 times) Warning output end
I am a child. The display element 38 outputs a warning output.
Lights up. This lighting may be blinking. Next, referring to the flow chart shown in FIG. 5, FIG.
Embodiment Processing of communication unit of FA network system
The operation will be described. Communication with host FA network 11
Then, a communication packet is received (step ST11).
Check CRC and check if communication packet is OK? Judge
(Step ST12). Whether the communication bucket is OK
Clears the communication error counter and outputs the warning output
The output of the element 37 is turned off and the display element 38 is turned off.
Lights (step ST13), returns to step ST11,
Prepare for the next reception. Unless a communication error occurs,
The processing of steps ST11 to ST13 is repeated. What
The communication error counter indicates that a communication error occurs once.
This is a counter that increments by one every time. In step ST12, the result of the CRC check is determined.
As a result, if there is a communication error, the communication error counter is
Increment (step ST14), and then
Whether the count has reached 200? Judge (step
ST15). At the beginning of communication, 200 communication errors
Since no error has occurred, the determination is NO, and then a communication error occurs.
-Did the counter reach 100? Judge (step
ST16). At the beginning of communication, a communication error of 10
Since it has not reached 0 times, the determination is NO, and step ST1 is executed.
It returns to 1 and waits for the next reception. A communication error continues for each reception, and 100 times
Is reached, the determination in step ST16 becomes YES,
A warning output is issued from the output terminal 37 (step
At the same time, the display element 38 is turned on (ST17).
ST18). This warning output and warning table
Indicates that a communication error has occurred, but the system is still
This is an intermediate notification before going down.
Interlocking becomes easier. After lighting the warning display element 38,
After returning to step ST11 from step ST18,
If a communication error continues, the display element 38 remains lit.
As a result, the warning output remains ON. Communication error
If the count is continued 200 times, step ST15
Is YES, and proceeds to communication error processing (step
ST19). Specifically, the communication error processing is performed as shown in FIG.
As with the system, it outputs a power-off signal for the controlled object,
Switch control of control target from upper communication master to slave
For example, a process for outputting a signal for performing the above operation. FIG. 6 shows an alternative to the display element 38 of FIG.
Such a frequency indicator may be used. This frequency indicator
Indicates the number of communication errors from 10 to 200
If it exceeds 100, the display color will change and its segment
Is blinking. This frequency indicator 38
According to the report, how much communication error
You can know if it has occurred. In the above embodiment, the number of times of communication error
The number of errors is counted to determine the frequency of error occurrence.
The communication error occurrence duration, and
They may be compared. [0022]【The invention's effect】 According to the invention,Next effect (1),
(2) is obtained. (1) The reliability of the system can be ensured. (2) Before the system goes down completely, for example, the user
Sees its output and strengthens the communication cable noise countermeasures.
And other measures can be taken. This allows the system
User recognizes that there is a margin until the system goes down
Yes, and the reliability of the system can be increased. [0023]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a device configuration example of an FA network system. FIG. 2 is a block diagram showing a schematic configuration of an FA network system according to an embodiment of the present invention. FIG. 3 is a flowchart for explaining a processing operation of a communication unit of the FA network system of the embodiment. FIG. 4 is a block diagram showing a schematic configuration of an FA network system according to another embodiment of the present invention. FIG. 5 is a flowchart for explaining a processing operation of a communication unit of the FA network system of the embodiment. FIG. 6 is a diagram showing a display example of the number of errors of a communication unit of the network system. [Description of Signs] 10 Upper communication master 11 Upper FA network 20 Slave _20-0 Communication unit _20-1 , ..., _20-4 Each slave 21 Subnetwork 23 Control target 24 Load power supply 35 Error output terminal

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-71036 (JP, A) JP-A-4-117895 (JP, A) JP-A-6-351078 (JP, A) JP-A-60-1985 10897 (JP, A) JP-A-2-25656 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/28 200 H04Q 9/00 351

Claims (1)

(57) [Claims] [Claim 1] An upper master and a communication unit are connected.
Configure a higher-level network, and configure a communication unit and multiple threads.
Connected to a different subnet from the host network.
Network, and each slave has a control pair
Elephant is connected, and the communication unit
Performs protocol conversion with the network, and
Slave is the upper network, communication unit, and subnet
Communication from the master
Ordinance controls the controlled object, and the controlled object is controlled separately.
In a control communication system that can also be controlled by local local devices , the communication unit receives packets from a higher-level master via a higher-level network.
A communication error check is performed each time communication is performed, and the upper network
Means for detecting the frequency of communication errors in the network, and a control pair connected to the slave via a sub-network.
Control of the elephant from the master
Error output that outputs a switching signal to switch to
Input terminal and the communication error frequency in the upper network have a first predetermined value.
If it exceeds, a communication error that outputs a switching signal to the error output terminal
Means for performing error processing, and the frequency of communication errors in the upper network being lower than a first predetermined value.
Exceeds a second predetermined value, which is a smaller number,
Notification means for notifying, and the communication error processing means of the communication unit is connected to the error output terminal.
By outputting the switching signal, the communication unit is connected.
Control of the control target connected to multiple slaves
Switch from control by host master to control by local device
A control communication system characterized by switching .