Automation equipment connected to a tcp/ip network

The present invention relates to automation equipment directly connected to a TCP / IP communication network.

The standard IP (Internet Protocol) protocol defines an interconnection protocol for communication networks at the network layer. The standard Transport Control Protocol (TCP) defines a data transport mechanism that guarantees end-to-end routing. These two protocols, which are widely used in global networks of the Internet, Intranet or Extranet type, are grouped together in this presentation under the term TCP / IP network.

Automation equipment hereinafter refers to a programmable logic controller, a control / command station, a digital control or any equipment that can contain and execute an application program with the aim of controlling and / or controlling all or part of a automation application belonging for example to the field of industrial automation, building automation or the control / command of electrical distribution networks. Automation equipment can also include business modules also equipped with processing units to perform specific functions relating to an automation business (such as weighing, regulation, positioning, etc.) as well as other modules. such as input / output modules. The modules of automation equipment are linked and synchronized with each other by an internal communication bus, generally called the backplane bus, which generally uses a proprietary protocol optimized for real-time I / O exchanges.

In automation equipment, it is known to have a communication module connected on the one hand to the internal communication bus of the automation equipment, and on the other hand connected to a TCP / IP network. This communication module acts as a gateway between the internal and proprietary communication services on one side and the TCP / IP network on the other.

However, under these conditions, it turns out to be very complex to maintain the characteristics of a communication according to the TCP / IP protocol from end to end between two entities communicating with each other. Indeed, the gateway of a network module cuts off the data flow of TCP and does not ensure the transparency of IP either. The advantages in performance, reliability and transparency provided by the TCP / IP protocol are thus lost.

Furthermore, a communication system is known in automation equipment which makes it possible to carry out, on the internal communication backplane bus, exchanges of information in accordance with the TCP / IP communication protocol. To exchange information that conforms to the TCP / IP communication protocol with each other, the modules of the automation equipment include their own IP address and a TCP / IP stack that can be executed by the processing unit of these modules. In addition, the automation equipment includes a network module, connected to an external TCP / IP network and to the internal backplane bus, allowing the automation equipment modules to perform directly on the TCP / IP network. information exchange in accordance with the TCP / IP communication protocol, via the internal backplane bus.

However, this solution uses the internal backplane bus of the automation equipment to route the TCP / IP communication, which can sometimes be detrimental for the performance of real-time communications linked to the automation application, and plus requires the use of a dedicated network coupler.

The aim of the invention is to provide automation equipment with direct access to the TCP / IP protocol for exchanges on a TCP / IP network, without having to resort to a gateway at the application layer, which can prove to be costly. . Thanks to the TCP / IP protocol, the automation equipment will be able to connect directly to business information systems (ERP Enterprise Resource Planning, MES Manufacturing Execution System) and will be able to use WEB protocols and architectures, for example UDP, HTTP, XML, WAP, FTP, SMTP, SNMP, DHCP, DNS, etc ... In addition, the invention proposes to manage the TCP / IP communication directly in the central unit of the automation equipment, without going through the backplane bus, while retaining control of the various assignments of the central unit. so that communications via the TCP / IP network do not interfere with the real-time operation of the application program controlling / commanding the automation application. In addition, the backplane bus can be advantageously reserved for exchanges of the input / output type or of the real-time message type (reflex messages, for example) of the automation equipment.

For this, the invention describes an automation device comprising a central unit which has at least one memory comprising a real-time operating system and an application program responsible for performing control or command functions in an application. automatism. The automation equipment includes a TCP / IP network driver which is directly integrated into the central unit without going through a backplane bus, the operating system of the central unit including a communications management module on the TCP / IP network and a slaving task responsible for slaving the execution of the communications management module to the characteristics of the automation application so as not to disturb the operation of the application program.

According to one feature, when the execution of the application program is in periodic mode, the control task comprises validation means making it possible to authorize the operation of the communication management module between the end of a cycle of the program d. application and the start of the next cycle. Furthermore, when the execution of the application program is in cyclic mode, the servo-control task comprises validation means for authorizing, at the end of a cycle of the application program, the operation of the module for managing the applications. communications during a period configurable by a user.

According to another particular feature, the communications management module comprises a first sub-module which uses a memory area to store data transmitted or intended for the application program. The communications management module also includes a second sub-module which uses a memory area to store data transmitted or intended for the TCP / IP network.

According to another feature, the first submodule of the communications management module transmits the data coming from the automation application program to the second submodule of the communications management module to build a message transmitted over the TCP network / IP.

According to another feature, the second submodule of the communications management module transmits the information representative of the messages coming from the TCP / IP network to the first submodule of the communications management module in order to be used by the program. 'application.

The information representative of the messages received from the TCP / IP network are in particular commands for updating the application program, commands for modifying the execution parameters of the application program, the consistency of which must be ensured by the application program. 'user. Likewise, the data stored by the first submodule coming from the application program are in particular indications of the operating state of the automatic system, the consistency of which must be ensured by the user.

According to another particular feature, the TCP / IP network driver executes a routing procedure for messages received from the TCP / IP network which is based on the priority levels contained in the IP addressing.

The invention, with its characteristics and advantages, is now detailed with reference to the appended drawings in which:

- Figure 1 shows the diagram of a communication architecture of an automation equipment according to the principle of the invention,

- Figure 2 shows schematically an example of architecture of such automation equipment.

The automation equipment according to the invention comprises a network connection controlled by a driver (40) supporting the TCP / IP protocol. The automation equipment comprises, in a known manner, a central unit (1) comprising at least one processor (5) and a memory bus (101) for exchanging with a random access memory (3) and with a read only memory (2). ). The automation equipment also includes an internal communication bus (100), called the backplane bus in this document, an input-output manager (21) as well as a real-time message processing manager (23 ), these managers being connected to the backplane bus (100) of the automation equipment. The read only memory (2) comprises the manufacturer's program (10) or operating system of the automation equipment responsible for controlling and commanding the execution of an application program (20) or user program usually stored in the RAM (3) of the automation equipment. It is recalled that, to control and / or command an automation application, the application program (20) processes input-output data whose transfer is carried out by the input-output manager (21) and manages coupling data from several devices, the transfer of which is carried out by the real-time message processing manager (23). According to the invention, the automation equipment comprises a TCP / IP network driver (40) which is directly integrated into the central unit (1) by a specific software bus (102), without using the bus (100). backplane, and which connects the automation equipment to the TCP / IP network (4).

The operating system (10) of the automation equipment also comprises a scanning manager (11) responsible for generating the sending of start of cycle (111) and end of cycle (110) signals of the program. 'application (20). These signals are sent to the input-output manager (21) and to the real-time message processing manager (23) so as to synchronize them with the progress of the application program (20).

According to the invention, the operating system (10) of the automation equipment also comprises a module (30) for managing communications with the TCP / IP network (4) and a slaving task (12) of this module (30).

The communications management module (30) provides the interface between on the one hand the application program (20) which executes the automation control / command functions and on the other hand the TCP / IP network (4). . This software consists of two sub-modules (31,32).

A first sub-module (31) presents data which can be easily exploited by the application program (20) because they are consistent and compatible with the format of the objects used by the application program. Their use therefore does not involve any additional processing liable to degrade the real-time performance of the system. In addition, the application program (20) and the submodule (31) share the same memory areas in the random access memory (3). These data are, by way of example, processing results of the application program such as history files, setpoint values, diagnostic information, etc.

A second sub-module (32) receives the messages from the network (4) which are not intended for the manager module for processing real-time messages (23). Thus, a routing procedure is executed by the pilot (40) to distinguish the real-time messages intended for the manager (23) and the other communication messages intended for the module (30). According to one embodiment, this routing procedure is based on the use of a given owner port which is reserved for real-time messaging circulating on TCP / IP. According to another embodiment, this routing procedure is based on priority levels contained in the IP addressing and which are being standardized at the level of the IETF (Internet Engineering Task Force), for example in the IPv6 protocol. . As an indication, the referral could also be made from the application protocol used; the WEB protocols would then be directed to the sub-module (32) for receiving messages from the network (4).

The submodule (32) exposes, via a random access memory (36), the data it receives in a format understandable for the submodule (31), which translates them into data that can be used by the program application (20). When a message is intended for the communications management module (30), it is sent via the link (35) to the second submodule (32). The message is first stored in the memory (36). The second submodule (32) then extracts the information from the message and transmits it to the first submodule (31) for processing. Optionally, this information can be stored in an intermediate buffer memory (33) so as not to be lost in the event that the execution of the communications management module (30) is interrupted. The first sub-module (31) then executes the commands representative of the information extracted from the incoming message. Conversely, for the transmission of a message or for the response to an incoming message, the first submodule (31) sends the information that it has received as represented by the arrow (34), to the second submodule ( 32). The second submodule (32) then constructs, from the information received from the module (31) and stored in its memory (36), a message conforming to the TCP / IP protocol.

According to the invention, the communications management module (30) is a background application, i.e. its execution has a lower priority than the priority of the application program with regard to the use of the resources of the automation equipment.

To do this, the operating system (10) comprises a slaving task (12) of the communications management module (30). This slaving task (12) manages, via a link (120), the allocation time of the central unit and the allocation of memory resources which are dedicated for the communications management module (30), in a manner that the execution of the application program (20) is not disturbed by the background execution of the communications management module (30). According to the invention, the slaving task (12) sends signals via the link (120) to the communications management module (30), on the one hand to validate or invalidate its execution and on the other hand to affect the memory resources and the time taken to allocate the central unit (1) to the execution of the instructions of the module (30) for managing communications.

When the operation of the application program (20) is periodic, each start of the cycle of the application program is triggered only after a determined period of time. This period of the application program cycle (20) is generally chosen by the user depending on the type of automation application to be controlled. In the event of periodic operation, the slaving task (12) validates the execution of the communication management module (30), by a first signal of determined level supplied on the link (120), between on the one hand the signal end of a cycle (110) and on the other hand the signal (111) of the start of the next cycle of the application program (20), generated by the scanning manager (11) and sent to the input / output manager (21) and to the manager for processing real-time messages (23). During the execution of a cycle of the application program (20), the slaving task (12) invalidates the execution of the communications management module (30), by a second level of signal transmitted on the link ( 120). The invalidation consists of putting the execution of the communication management on standby, so that when the first level of validation signal is again received on the link (120) by the communication management module (30) , the execution of the communications management module (30) resumes where it was stopped. Thus, the task (12) is always synchronized with the I / O exchanges of the automation equipment.

When the execution of the application program (20) is not periodic but cyclical, i.e. the start of a cycle of the application program is not linked to the start of a period determined but depends on the end of the previous cycle, the slaving task (12) validates the execution of the communications management module (30), by a signal on the link (120), for a certain period of time, at the end of an application program cycle. This period of time dedicated to the module (30) is initially set by default but the user advantageously has the possibility of configuring it to optimize it while ensuring that the execution of the application program (20) is not disturbed by the execution of the communications management module (30). The start of the next cycle of the application program (20) is then triggered only when the time dedicated to the module (30) has elapsed or when the module (30) has no more tasks to perform. The parameter setting value for this duration is determined by the user according to the needs of the automation application, for example.

It will be understood that the communications management module (30) and the corresponding slaving task (12) make it possible to provide the automation equipment with a communication function with a TCP / IP network (4) without disturbing the system. '' real-time execution of the automation application program and without using the backplane bus of the automation equipment. Thus, an information system connected to the TCP / IP network (4) of the automation equipment according to the invention can directly access information from the automation equipment without disturbing it through the intermediary, for example , an Internet type browser, insofar as the communications management module (30) supports the corresponding protocol.

It should be obvious to those skilled in the art that the present invention allows embodiments in many other specific forms without departing from the scope of the invention as claimed. Therefore, the present embodiments should be considered by way of illustration, but may be modified within the field defined by the scope of the appended claims, and the invention should not be limited to the details given above.