JPH11220509A - Communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute quickly and surely update of an output, when the update of an output of a specific control device is required in a communication system in which a signal is communicated between a host controller and plural control devices, to which an address is given respectively via a communication channel. SOLUTION: This communication equipment 1 used between a host controller 2 and plural control devices 4 is provided with a storage means 1a that stores a numeral denoting an address received from the host controller 2 and other information and with a processing means 1b that conducts write/read of a numeral to/from the storage means and update processing of output from the control devices 4. When the host controller 1 designates the address of a specific control device 4, the processing means 1b interrupts the normal output update processing to execute the output update processing of the specific control device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a higher-level control device in a communication system for transmitting and receiving signals via a communication path between a higher-level control device (controller) and a plurality of control devices each assigned an address. The present invention relates to a communication device used between the control device and a plurality of control devices.

[0002]

2. Description of the Related Art As an example of the above communication system, "CAN"
(Controller Area Network) protocol using a specific protocol (communication protocol) called "SDS (Smart
A communication system called "Distributed System)" is known. This system (SDS) performs communication according to a CAN protocol. The CAN protocol has the following characteristics, a high transmission speed, and a high resistance to noise. High environmental resistance.

[0003] The line form according to the CAN protocol is a two-wire bus type, and the two lines are respectively CAN-H and CAN.
When -L is set, the signal is at logic level 0 when the voltage between HL and 2V is 2V, and is at logic level 1 when the voltage between HL and 0L is 0V. When the logical level 0 and the logical level 1 are close on the bus, the logical level 0 has priority. The use efficiency of the bus is high, and signal transmission on the order of several milliseconds is possible. "Short Form" and "Long Form" are defined in the CAN data frame, and the data field in the data frame defined by "Long Form" has a data length of 0 to 8 bytes.

Each node (connecting device) on the bus compares its own transmission data with the data on the bus in the "Arbitration Field" (designated area of priority for acquiring the right to use the bus) in the data frame. If the two data are different, it recognizes that another node having a higher priority than itself is transmitting, and stops transmitting. Then, the data frame is monitored and “CRC (Cyclic Redundancy Checker)
k), if it is determined to be normal by the check bit, the first bit of the "ACK Field" (reception recognition area) is set to the logical level 0.

[0005] SDS using the above CAN protocol
Can connect nodes such as a bus master and up to 126 sensors and actuators on a single bus. And
Since the data frame is small at the level of sensors and actuators, SDS is used to control various slave devices such as mass flow controllers, vacuum gauges, sensors, or actuators such as valves in industrial equipment, as control devices as multiple nodes. , And is suitable as a communication system for transmitting commands to each node at a high speed from a higher-level controller via a communication interface, and taking in various information output from each node.

In a communication system such as the SDS described above, each node is assigned a unique address, and by specifying those addresses, transmission of control commands to each node and collection of information from each node are performed. Do the work. Such work is essentially the work of the system controller, but with the sophistication and complexity of production equipment,
From the viewpoint of decentralized control or reducing the load on the controller, it is known to provide a communication device called an interface module between a higher-level control device such as a system controller and a node, and to share the work with the communication device.

In this case, the communication device performs input / output processing on a plurality of nodes, and therefore, priorities are set for the addresses of the respective nodes. Then, when performing the above-described operation for each node, the communication device performs necessary processing in order from the node having the address with the highest priority. Therefore, for example, even when updating the output from a node, the output is updated in accordance with the priority of the address of each node. Here, the output update is to replace existing information output from the node with new information.

[0008]

However, there is a case where it is desired to update the output as described above quickly for a specific node regardless of the priority. For example, in the case of a system that operates an actuator in accordance with the content detected by a sensor, detection data (existing information) sent from a node to which the sensor is connected is converted to new data when new detection data is generated. It needs to be rewritten (updated data). In such a case, according to the conventional technology, it is checked whether or not the information of the node having the first-order address has no change even if the output data does not need to be updated if there is no change. Must go through the process of doing.

In fact, when updating the output from a node, the output data from the specific node to be updated must be compared with the existing data. It takes time to compare and judge in order to detect a specific node. For example, the output update time from the upper node to the lower node may be as long as tens of seconds to several minutes.

In particular, in a communication system in a manufacturing facility such as a semiconductor manufacturing apparatus or an electronic component assembling apparatus, output information of many nodes is hardly updated simultaneously in a series of processing operations, and priority is given to a specific node. In many cases, you want to perform an update process.

Therefore, in the SDS, the updating process is performed by interruption. However, interrupt processing corresponding to a reception request (message) from a node is frequent (for example, is performed at the fastest interval of 60 microseconds). Therefore, in the conventional update processing, output update for a lower node is achieved. It was difficult.

It is an object of the present invention to provide a communication apparatus capable of promptly and accurately executing an output update for a specific node in a communication system as described above when the output needs to be updated.

[0013]

According to a first aspect of the present invention, there is provided:
A communication device used between a higher-level control device and a plurality of control devices in a communication system for transmitting and receiving signals via a communication path between a higher-level control device and a plurality of control devices each having an address. Storage means for storing a numerical value or other information indicating an address input from a higher-level control device, and processing for writing a numerical value to the storage means, reading from the storage means, and updating output from a control device Means, when an address of a specific control device is designated by a higher-level control device, the processing unit interrupts a normal output update process and performs an output update process of the specific control device. It is characterized by the following.

According to a second aspect, the information stored in the storage means includes information for specifying a control device which performs output update processing with priority and information for requesting execution of interrupt processing.

In a third mode, an interrupt is generated, which is separate from the above processing means, and performs processing in response to a request issued from a higher-level control device so as to interrupt normal output update processing and update output of a specific control device. / Detection unit.

In a fourth mode, an address of a specific control device and an added value N thereof are designated by a higher-level control device, whereby the specific control device and the N before or after this control device are specified.
The output update process is preferentially performed with respect to the control device having the first address.

[0017]

According to the first aspect of the present invention, when the address of a specific control device is specified, the output update process is interrupted in the middle of the normal output update process, and the output update process is preferentially performed for the specific control device. Done. For this reason, the processing time is much shorter than in the conventional method in which the processing is performed sequentially from the node having the address with the higher priority.

According to the second aspect, the storage means stores the information for specifying the control device which performs the output update with priority and the information for requesting the execution of the interrupt.
As long as the information is input to the higher-level control device, the communication device promptly executes the output update process for a specific node as needed according to the information written in the storage means.

According to the third aspect, the processing for specifying the control device to be preferentially updated and the processing for detecting the data to be updated are executed by the processing means, but the interrupt processing is provided separately. The interrupt generation / detection unit executes in response to a request from the host control device. Thereby, the processing procedure in the processing means is simplified, and the entire processing is performed quickly.

According to the fourth aspect, for a specific control device and a control device having an N-th address before or after the specific control device, the output update process is preferentially performed by interrupting the normal output update process. Therefore, even when the user wants to update the output information by specifying a plurality of control devices at the same time, the user can easily achieve the update.

[0021]

FIG. 1 is a block diagram showing a basic configuration of a communication apparatus to which the present invention is applied in a communication system such as the SDS.

In FIG. 1, a communication device 1 includes a storage unit 1 necessary for performing an output update process described later according to the present invention.
a and a processing means 1b, and a communication interface 1c required for communication processing with an external device.

The storage unit 1a is a storage unit for numerical data, and is configured to be readable and writable. As such storage means, for example, in the case of "SDS", the entry of the data to be written and the exit of the read data are shared, and either one is selected by a control signal designating write or read. Is generally used. The processing means 1b is constituted by a CPU or a ROM (read-only storage device) as an arithmetic device. The communication interface 1c has a transmission / reception unit including a signal conversion circuit including a buffer.

In the communication system shown in FIG. 1, a communication device 1 is interposed between a host controller 2 and a plurality of control devices (the above-mentioned nodes) 4. Based on the above-mentioned CAN protocol, a plurality of communication devices or control devices having a communication function are connected to a common bus (main line) 5a, and have a communication function via a branch bus (branch line) 5b branched from the common bus 5a. A plurality of nodes 4 are connected. That is, the communication device 1 is connected to the bus 5a connected to the communication interface 1c.
And 5b are connected to each node 4.

The controller 2 comprises a system controller functioning as a master controller of the SDS, or a personal computer programmed to realize such a function. In any case, any device may be used as long as it has input means for the user to input commands and numerical values. The numerical values and the like input thereto are transmitted to the communication device 1 and stored in the storage unit 1a. Then, processing such as output updating is performed by the processing means 1b. The communication interface 1c communicates with each node 4 connected thereto.
Transmission of control commands and the like processed by the communication device 1, each node 4
It receives output information from the server.

In this communication system, an address is set for each node 4, and usually, according to the priority of the address stored in the storage means 1a in advance.
The output update processing of each node 4 is performed.

Here, when it is desired to update the output by interrupting the normal output update processing for a specific node 4, information for that is transmitted from the controller 2 and stored in the storage means 1a of the communication apparatus 1. At that time, the processing unit 1b compares the node information (output data and address value of each node) stored in the storage unit 1a, which is recognized at the time of system startup and at the time of reset, with information for output update. , An output update process is performed by specifying a node.

FIG. 2 is a block diagram showing a basic configuration of a communication system including a communication device 1 'of another embodiment.
Here, the communication device 1 ′ includes an interrupt generation / detection unit 1d connected to the storage unit 1a and the processing unit 1b in addition to the configuration of FIG.

The interrupt generation / detection unit 1d generates a signal requesting execution of an interrupt in order to speed up the processing of the processing unit 1b. This interrupt execution request signal is obtained by writing the node address specifying information of the node 4 from the controller 2 to the storage means 1a, and at the same time, detecting that the specific information has been written to the storage means 1a by the interrupt generation / detection unit 1d. And is sent to the processing means 1b.
Therefore, the user only has to write data from the controller 2 to the storage unit 1a, and the interrupt generation / detection unit 1
From d, a signal requesting execution of an interrupt can be generated.

The identification of the node 4 and the comparison between the existing data and the updated contents are executed between the processing means 1b and the storage means 1a, while the processing means responds to the interrupt request generated from the interrupt generation / detection section 1d. In 1b, the normal output update processing is interrupted, and the output update processing is preferentially performed for a specific output control device. Thereby, the processing procedure in the processing means 1b is simplified, and the entire processing is performed quickly.

The interrupt execution request signal indicates that an interrupt /
Although it is generated by detection by the detection unit 1d, it may be generated by a command from the controller 2. That is, as shown in FIG. 3, after writing the node address specifying information of the node 4 from the controller 2 to the storage unit 1a, the interrupt generation / detection unit 1d of the communication device 1 ″ executes the interrupt execution in response to a command from the controller 2. A request signal is generated and sent to the processing means 1b.

In the communication device 1 ″ of FIG.
Is specified between the processing means 1b and the storage means 1a, while the processing means 1b is operated in accordance with the interrupt request generated by the interrupt generation / detection unit 1d as described above. Then, the normal output update processing is interrupted, and the output update processing is preferentially performed for a specific output control device.

FIG. 4 is a conceptual diagram showing the contents of information stored in the storage means 1a. That is, in the storage area of the storage unit 1a, the information 11 of the interrupt request, the node information (input / output data) 13, and the other information 12 are stored at predetermined locations. In addition, other information 12
Is used when performing processing other than output updating.

Next, the procedure for updating the output of the node 4 in the system configuration of FIG. 1 will be described with reference to FIG. S1, S2,... In the figure indicate the number of the procedure (step).

When the communication device 1 transmits numerical data as a request from the controller 2 to interrupt the right of output update to a specific node, the processing means 1b executes
In step 1, the numerical data is stored in the storage unit 1a. Then, in S2, it is determined whether or not there is an interrupt request for preferentially updating the output to a specific node by accessing data in the storage unit 1a periodically.
If there is no request, normal output update is performed in S3, but if there is an interrupt request, the process proceeds to the interrupt request processing in S4.

In the processing of the interrupt request, it is determined in S5 whether or not the content of the interrupt request is appropriate. If the content of the interrupt request is not appropriate, the interrupt request is disabled and the interrupt processing ends in S6. If the content of the interrupt request is appropriate, the execution of the interrupt request is determined, and in S7, the existing node information stored in the storage unit 1a is accessed for information such as the address of the node to be output updated preferentially. While determining the address of a specific node.
Then, in S8, it is determined whether or not the output data requesting the output update for the specific node has changed from the existing data. Here, if there is no change, the interrupt processing ends in S6, and if there is a change, a frame of an output update request is created in S9, and the frame is transmitted to a specific node via the communication interface 1c in S10. Then, the output is updated. Then, after the execution is completed, the process returns to the normal output update process (S3).

Next, the procedure for updating the output of the node in the system configuration of FIG. 2 will be described with reference to FIG.

In the system shown in FIG. 2, processing is performed by the processing means 1b in accordance with the signal generated by the interrupt generation / detection unit 1d as described above. First, similarly to the procedure of FIG. 5, the processing unit 1b stores the numerical data in S1 in the storage unit 1a.
In S2, it is determined whether there is an interrupt request for preferentially updating the output to a specific node. If there is no request, normal output update is executed in S3, and there is an interrupt request. In this case, the processing shifts to the processing of the interrupt request in S4, but the processing after this interrupt request is executed by the interrupt processing routine of the processing means 1b. That is, in S5, it is determined whether or not the content of the interrupt request is appropriate. If not, it is determined that the interrupt request cannot be made, and the interrupt processing is terminated in S6. On the other hand, if the content of the interrupt request is appropriate, S1
In step 1, a request for the highest priority processing is set. The highest-priority process is to process a specific node preferentially.

The highest priority processing (S12) is performed in S7 to S in FIG.
This is performed in the same procedure as in step 10. That is, the processing means 1b
Specifies the node address to be processed while accessing the storage unit 1a in S7. Then, in S8, it is determined whether the output data for the specific node address has changed by comparing with the existing data. If it is determined that the output data has changed compared to the existing data, a frame requesting output update is created in S9, the frame is transmitted to a specific node, and the output update is executed in S10. Is done. When the output update processing is completed, the request for the highest priority processing is cleared in S20, and the process proceeds to the normal output update processing (S3). On the other hand, if it is determined in S8 that there is no change compared to the existing data, the request for the highest priority processing is cleared in S20, and the process proceeds to the normal output update processing (S3).

FIG. 7 shows a modification of the highest priority processing shown in FIG. 6. In the system configuration shown in FIG. 2, output updating is continuously performed on a plurality of designated nodes by interrupting the normal output updating processing. FIG. 6 is a flowchart showing a procedure in the case of performing the operation.

In the highest priority processing S13 of this example, the processing up to S10 is performed in the same procedure as the highest priority processing S12 of FIG. However, if “NO” in S8 or after the output update process in S10, in S14, the processing unit 1b determines whether there is a request to be subsequently processed.
In S15, the processing shifts to the processing of one priority lower, and in S1
In step 6, a specific node address to be processed is read, and the process returns to step S7 to repeat the following process. On the other hand, S14
In step S20, when it is determined that there is no request, that is, when all the requested continuous processes have been completed, the request for the highest priority process is cleared in step S20, the process returns to the normal output process in step S3, and the process ends.

Next, a description will be given of a procedure in which when a user wants to update the output of a specific node, the user actually inputs the data from the controller 2 and stores it in the communication device.

First, as numerical data to be read into the storage means 1a of the communication apparatus, an address (hereinafter, referred to as a head node address) X of a node to be updated first is designated. For example, when the designated start node address is written in the storage unit 1a as X = 16, the output update processing for the node at the address 16 is performed by interrupting the normal output update processing, and thereafter, the normal output update processing is performed. Is returned to.

When it is desired to update the output by designating a plurality of nodes as shown in FIG. 7, the leading node address is designated as X, and at the same time, the address addition value N is written into the storage means 1a, so that the address is continuously updated. Update processing is performed. That is, a node whose address is from X to X + N is designated as an interrupt update target. For example, if the start address is written into the storage unit 1a with X = 16 and the added value is N = 3, four nodes having addresses 16, 17, 18, and 19 are designated as interrupt update targets, and are successively interrupted. The process is performed, and after the process, the process returns to the normal output update process.

Next, an example of a system using the present invention will be described.

FIG. 8 shows the driving of a belt conveyor in an automatic assembly line for components in which, for example, by driving the belt conveyor, the components placed thereon become a moving body 20 and are conveyed from left to right. The sensor A and the sensor B capable of detecting the moving body 20 are arranged at predetermined intervals in the direction, and the sensor B is installed at a position higher than the sensor A. Here, the address of the node connecting the sensor A and the sensor B is set as the head node address.

According to this configuration, when the sensor A first detects the component 20 as a moving body, the sensor B issues an instruction from the node so that the component B can be immediately detected. When detected, the light emitting unit (LED) 2
By turning on 1, an instruction to move the component 20 to another process can be issued. That is, when the size of the component 20 is not constant, and when the component 20 is detected by the sensor B, the LED 21 instructing to move to another process is provided.
Lights up. On the other hand, when the component 20 is not detected by the sensor B, the LED 21 is not turned on and the process proceeds to a normal process. In this case, the node to which the LED 21 is connected is a target of output update.

As shown in FIG. 9, when a display unit 31 having a display function and a stop button (emergency control button) 32 and the like are mixed on the control panel 30, control according to the input of each stop button and the like is performed. By performing an interrupt process by designating a node address for each output function of the panel 30, that function can be achieved.

The communication apparatus of the above embodiment is effective when one node cannot be divided into display, output, analog, digital, and the like. That is, since it does not take much time to update the output due to the interrupt processing, as shown in FIG. 10, the nodes are independently provided for the functions of the display node 41, the output node 42, the analog node 43, the digital node 44, and the like. Can be used. For example, a detection node (sensor)
When the output is updated from the display node to the display node (LED), the result is as shown in FIG.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a communication device to which the present invention is applied.

FIG. 2 is a block diagram showing another embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration in which a part of the embodiment of FIG. 2 is modified;

FIG. 4 is a conceptual diagram showing an internal structure of a storage unit in the communication device.

FIG. 5 is a flowchart showing a procedure for updating output of a node in the system configuration of FIG. 1;

FIG. 6 is a flowchart showing a procedure of updating output of a node in the system configuration of FIG. 2;

FIG. 7 is a flowchart showing a procedure of updating output to a plurality of nodes in the system configuration of FIG. 2;

FIG. 8 is a diagram showing a usage example of the communication device of the present invention.

FIG. 9 is a diagram showing another usage example.

FIG. 10 is a diagram showing still another usage example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Communication apparatus, 1a ... Storage means, 1b ... Processing means, 1c
... Communication interface, 1d ... Interrupt generation / detection unit,
2 Upper controller, 4 Node, 5a Main line, 5b
... branch line, 20 ... moving body, 21 ... LED, 30 ... control panel,
31: display section stop button, 32: stop button.

Claims (4)

[Claims] 1. A communication system for transmitting and receiving signals via a communication path between a higher-level control device and a plurality of control devices each having an address, between a higher-level control device and a plurality of control devices. A communication device to be used, comprising: a storage unit capable of storing a numerical value and other information indicating the address input from the higher-level control device; writing a numerical value to the storage unit; reading the numerical value; Processing means for performing output update processing from the device, when the address of a specific control device is specified by the higher-level control device,
A communication device, wherein the processing unit interrupts a normal output update process and performs an output update process of the specific control device. 2. The communication device according to claim 1, wherein the information stored in the storage unit includes information for specifying a control device that performs output update processing with priority and information for requesting execution of interrupt processing. A communication device, characterized in that: 3. The communication device according to claim 1, wherein said higher-level control device issues an output of said specific control device by interrupting a normal output update process separately from said processing means. Occurrence of interrupt for processing request /
A communication device comprising a detection unit. 4. The communication device according to claim 1, wherein the higher-level control device designates the address of the specific control device and the added value N thereof, whereby the specific control device and the control device are controlled. A communication apparatus for performing output update processing preferentially between a device and a control device having up to N-th address before or after the device.