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AssigneeSiemens Aktiengesellschaft
InventorsThomas Bauer, Roland Heymann, Heinz-Christoph Schmolka, Marcus Sebald, Thomas Talanis, Frank Volkmann
Estimating the term…
OPC data is transmitted via data networks, in particular the Internet. A bi-directional data connection via the Internet in both directions, is enabled even across firewalls and starting from an OPC client, which is not visible as a server on the Internet. To achieve this, a first connection request for establishing a first transmission channel is sent from a first data processing device of an OPC client, via a data connection, to an OPC server of an automation system. The OPC server responds to the request using a second transmission channel. The data connection is thus kept open permanently, allowing data to be sent and received bi-permanently, allowing data to be sent and received bi-directionally, said operations being temporally independent of each other, between the OPC client and the OPC server by at least one data network, in particular, the Internet. To guarantee a temporally unlimited service life of a data connection, dummy data is transmitted, for example, at regular intervals from the OPC server to the OPC client, even if no useful OPC data is present, in order to maintain at least one data connection.
A method for transmitting OPC data via data networks, in particular the Internet (10), in which a first connection request for establishing at least one first transmission channel (6a, 7a, 8a) is sent from an OPC client (1) via a data connection (6, 7, 8) to at least one OPC server (4), at least one data connection (6, 7, 8) being permanently open, which is provided for sending, at any desired time and independently of the actions of the OPC client (1), OPC data from at least one OPC server (4) to the OPC client (1) via at least one data network.
The method as claimed in one of the preceding claims, characterized in that when useful OPC data is not present, dummy data is transmitted from the OPC server (4) to the OPC client (1) every 25-35 seconds.
The method as claimed in one of the preceding claims, characterized in that in order to maintain a data connection (6, 7, 8) permanently, the OPC server (4) sends to the OPC client (1) information which informs the OPC client (1) that a transmission of data is intended.
The method as claimed in one of the preceding claims, characterized in that in order to maintain a data connection (6, 7, 8) permanently, via which quantities of data up to a defined size are transmitted from the OPC server (4) to the OPC client (1), a requirement for a new connection request is sent from the OPC server (4) to the OPC client (1) before the defined quantity of data is reached, and then a new connection request for establishing at least one new transmission channel is sent from the OPC client (1) to the OPC server (4).
The method as claimed in one of the preceding claims, characterized in that the quantity of data to be transmitted via one transmission channel have a size of 15-25 MB.
The method as claimed in one of the preceding claims, characterized in that a transport protocol, in particular an Internet transport protocol, is provided to control the data transmission.
The method as claimed in one of the preceding claims, characterized in that the transport protocol provided is a Hypertext Transport Protocol.
The method as claimed in one of the preceding claims, characterized in that the method is provided for operating and observing an automation system (5) via at least one data network, in particular via the Internet (10).
The method as claimed in one of the preceding claims, characterized in that before being sent via the Internet by a transmitting station, the OPC data is converted into an Internet-compatible data format and sent via the Internet to a receiving station and, following the transmission, the data received in the Internet-compatible data format is converted into OPC data again by the receiving station.
The method as claimed in one of the preceding claims, characterized in that the OPC client (1) is not visible in the Internet (10).
The method as claimed in one of claims 1 to 13, characterized in that the OPC client (1) has not installed an Internet Information Server.
The method as claimed in one of the preceding claims, characterized in that the operating and observation sytem (1) of the OPC client (1) initiates the provision of at least one transmission channel (6a, 7a, 8a) as a distributed object, in particular as a DCOM object, and in that the establishment of the connection to the automation system (5) is carried out via a DCOM server (4) and/or an OPC server (4).
A system for transmitting OPC data via data networks, in particular the Internet (10), comprising at least one data processing device (1) that can be coupled to a data network and belongs to an OPC client (1), the first data processing device (1) being provided to establish at least one data connection (6, 7, 8) in the form of a first transmission channel (6a, 7a, 8a) to at least one OPC server (4), at least one data connection (6, 7, 8) being permanently open, which is provided for sending, at any desired time and independently of the actions of the OPC client (1), OPC data from at least one OPC server (4) to the OPC client (1) via at least one data network.
Dependencies are inferred from the claim text.