Section: Proxies

The section Proxies defines a function block which implements the proxy.

A proxy serves for data exchange of modules of different application. The instance of the proxy FB represents the module instance in a remote application.

SEC Proxies                                    //optional: yes, modifier: [UPDATE]
    SEC Proxy : <identifier>                   //optional: yes, modifier [UPDATE]
            FB := <FB name>;                       //optional: no, type: QID
            SEC MirrorVar : <identifier>           //optional: yes, modifier [UPDATE])
                    Variable := <variable name>;       //optional: no, type: VarPath
            END_SEC
            SEC ProxyParameter : <target>          // optional: yes, modifier [UPDATE]
                    Variable := <InstancePath>;        // optional: no, type: VarPath
            END_SEC
    END_SEC
END_SEC

Details regarding the syntax of definition types are described in the section Module Declaration.

. Specification:

The function block must derive from IBaseInstance.
The function block must have a method SetProxyIdentification with the following signature, which is not included in the Interface IBaseInstance:
SetProxyIdentification(pbyName : POINTER TO BYTE, udiComAddr : UDINT, udiLocalComAddr : UDINT, pEnvironment : MEnv)
The passed instance name and the set address must be returned from the properties InstanceName, ComAddress, and LocalComAddress.
The function block must not derive from IModule.
The section MirrorVar allows to mirror a variable of a module instances to its proxy instances. For this the instance path of the variable has to be declared in the definition Variable, which has to be stated in form of a relative (to the module instance FB) path. The following rules apply to the specified variable of the module instance FB:
- The variable has to be part of the module instance FB's Vars, Inputs or Outputs.
- It must be defined in the module FB as well as in the proxy FB
- It must be from the same type in both FBs
- It must have a primitive type; thus no pointers, interfaces or structs as a whole are allowed for mirroring, but only simple types (numeric, STRING, TIME, etc.)
If the specified variables meet these conditions, they are automatically transferred as part of the RMP without the user having to worry about the transfer any further.
The section ProxyParameter allows to define parameter for the proxy. The following points should be taken into account:
- The target of the ProxyParameter must correspond to a parameter target of the module
- The variable of the proxy module must match the type of the variable used for the module parameter. Only primitive types and enumerations are allowed
- The proxy parameters are set once to the value configured in the module instance during the initialization phase of the respective application. While the application is running, these variables are not mirrored in the proxies
The name of the function block can be qualified with a namespace path.

Example 25. Example

SEC Proxies
        SEC Proxy ProxyFB1
                FB := ProxyModule1;
                SEC MirrorVar : diInput
                        Variable := diInput;
                END_SEC
                SEC ProxyParameter : InParam1
                        Variable := TL.Input1_Name;
                END_SEC
        END_SEC
END_SEC