View source for IBH OPC UA:Client functions

==OPC Client==

One of the advantages is, that the '''IBH OPC UA Server/Client''' supports Client and Server functions simultaneously.	

This allows data exchange between different OPC UA Servers.

For example control systems and other equipment with OPC UA servers from different manufacturers can exchange data with each other.


The configuration of the client functions will be made using a standard web browser.


=== Configuration of the Client Function ===


==== Add Server ====

First, the servers which shall communicate with each other need to be defined. The required security level must be chosen.

[[Image:IBH_Link_UA_Client_add_server.png|813px]]


[[Image:IBH_Link_UA_Client_Discovery_Servers.png|954px]]


==== Add Variable to read ====

As next step the variables to be read must be selected.


In addition, the sampling rate of the variable must be entered.


[[Image:IBH_Link_UA_Client_add_variable_read.png|686px]]


[[Image:IBH_Link_UA_Client_select_variable_read.png|809px]]


==== Change parameters of the Variable ====
The sampling intervall and the queue size can be changed:

[[Image:IBH_Link_UA_Client_Variable_Properties.png|904px]]

[[Image:IBH_Link_UA_Client_Variable_Change_Parameters.png|906px]]

==== Connect Variable ====

The value, time stamp and read status of variables can now be written into other variables.


[[Image:IBH_Link_UA_Client_connect_variable.png|801px]]

[[Image:IBH_Link_UA_Client_connected_variable.png|891px]]


=== Advantages of Client function ===

==== Communication between Controllers ====

The client function enables communication between different controllers. It is irrelevant, whether the controllers are connected to one or more OPC UA servers.


==== Communication between Controllers and other devices with OPC UA ====

There are more and more devices and sensors with integrated OPC UA servers on the market. 


The client function allows easy exchange of data with these devices.


==== Monitoring of the communication ====

The controller can easily monitor data connections via the time stamp and variable status using the client function:

===== 1. Monitoring the data connection to the own OPC UA server =====

Each OPC UA server contains the variable "Current Time":


[[Image:IBH_Link_UA_Client_Server_Time_Stamp.png|810px]]


This variable must be connected with a variable in the controller. The variable then must be monitored for changes in the controller logic.


If the variable does not change, there is no connection to the OPC Server. In this case, the controller or machine can be set in a safe condition.


===== 2. Monitoring of the Variable to be read =====

The OPC UA Server automatically monitors the variable to be read. If there is a fault, this is indicated in the variable status.

The meaning of the values are defined within the OPC UA specification. If the value is 0, everything ist fine.

This status variable therefore should also be connected to a variable in the controller and also should be monitored.


[[Image:IBH_Link_UA_Client_Read_Status.png|1041px]]