Automation device and method for optimized access to a variable

An automation device for process automation with an open platform communications unified architecture (OPC UA) server containing one or more variables of the process automation, wherein the OPC UA server for receiving write requests from a client in communication with the automation device is set up for write of at least one variable, the automation device being configured to:

• specify, at the OPC UA server of the automation device, a time period between two write requests for a same write request variable from the client, the OPC UA server determining the time period based on receipt times of the two write requests;
• specify, by the OPC UA server of the automation device, a sampling time for an address space in the OPC UA server for the write request variable as a function of the specified time period;
• enable write access to the write request variable in an address space of the OPC UA server at the respective sampling time, independent of a previous write request of the client;
• and
• determine the sampling time as a function of a determined time span between two write requests,
• wherein the automation device is set up:
• to store a variable value obtained in a received write request for a queried variable in a data structure;
• and
• to enable write access for the queried variable with the write request variable deposited in a data structure at the respective sampling time such that the client requests are decoupled from the write access for the queried variable.

A method for optimized access to at least one variable in open platform communications unified architecture (OPC UA) server of an automation device, the method comprising:

• receiving at least two read requests sent by a querying client for a same requested variable at the OPC UA server;
• determining by the OPC UA server of the automation device a time period between the two read requests for the same read request variable based on receipt times of the at least two read or write requests;
• determining by the OPC UA server a sampling time for the read request variable as a function of the time period;
• enabling read access to the read request variable in an address space of the OPC UA server at the respective sampling time, independent of future read requests of the client;
• and
• determining the sampling time as a function of a determined time span between two read requests,
• wherein the sampling time is selected such that it deviates by an offset from a future read request, and
• wherein a read request variable is a queried variable, the queried variable being the same read request variable:
• at the respective sampling time, the read access for the queried variable is carried out in the address space of the OPC UA server;
• a variable value for the queried variable obtained by the read access is stored in a data structure;
• and
• in response to a future read request, the variable value for the queried variable stored in the data structure is sent to the querying client by the OPC UA server such that the client requests are decoupled from the read access for the queried variable.

A method for optimized access to at least one variable in an open platform communications unified architecture (OPC UA) server of an automation device, the method comprising:

• receiving at least two write requests sent by a querying client for a same requested variable at the OPC UA server;
• determining by the OPC UA server of the automation device a time period between the two write requests for the same write request variable based on receipt times of the at least two write requests;
• determining by the OPC UA server a sampling time for the write request variable as a function of the time period;
• enabling write access to the write request variable in the address space of the OPC UA server at the respective sampling time, independent of a previous write request of the client;
• and
• determining the sampling time as a function of a determined time span between two write requests,
• wherein the sampling time is selected such that it deviates by an offset from a future write request, and
• wherein a write request variable is a queried variable, the queried variable being the same read request variable:
• a variable value for the queried variable obtained from the client in a received write request is stored in a data structure, and
• at the respective sampling time, the write access for the queried variable is carried out with the variable value for the queried variable stored in the data structure such that the client requests are decoupled from the write access for the queried variable.