System and method for transmitting data via data networks, in particular, the internet, using an asynchrinous data connection

The method as claimed in one of the preceding claims, characterized

• in that, in the absence of user data, dummy data are transmitted from the server (4) to the client (1) every 25-35 seconds.

The method as claimed in one of the preceding claims, characterized

• in that a data link (6, 7, 8) is permanently maintained by virtue of the server (4) sending the client (1) information which notifies the client (1) that transmission of data is intended.

The method as claimed in one of the preceding claims, characterized

• in that a data link (6, 7, 8) which the server (4) uses to transmit volumes of data up to a stipulated size to the client (1) is permanently maintained by virtue of the server (4) sending a request for a new connection request to the client (1) before the stipulated volume of data is reached, and the client (1) then sending a new connection request for setting up at least one new transmission channel to the server (4).

The method as claimed in one of the preceding claims, characterized

• in that the volumes of data to be transmitted via a 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, particularly an Internet transport protocol, is provided for controlling 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 for operating and observing an automation system (5) is provided via at least one data network, particularly via the Internet (10).

The method as claimed in one of the preceding claims, characterized

• in that the client (1) is not visible on the Internet (10).

The method as claimed in one of the preceding claims, characterized

• in that the operating and observation system (1) on the client (1) initiates the provision of at least one transmission channel (6a, 7a, 8a) as a distributed object, particularly as a DCOM object, and in that connection setup to the automation system (5) is effected via a DCOM server (4).

A system for transmitting data via data networks, particularly the Internet (10), having at least one data processing apparatus (1), which can be linked to a data network, on a client (1), where the first data processing apparatus (1) is provided for setting up at least one data link (6, 7, 8) in the form of a first transmission channel (6a, 7a, 8a) to a server (4), with at least one data link (6, 7, 8) being permanently open which is provided for sending data from the server (4) to the client (1) via at least one data network at any time independently of actions by the client (1).