This method always makes the data variable writable; however, its status code and source timestamp will not be writable, i.e. OPC UA clients will not be able to modify them. If you need a different behavior, use one of the WriteFunction(UADataVariable,Type,Func<UAAttributeData,UAStatusCode>) method overloads instead.

This method does not change the readability access of the data variable. By default, data variables are readable. If you need a data variable that is writable but non-readable, combine this method with calling Readable(UADataVariable,Boolean) method with the 'readable' parameter set to false.

Unless the write value action throws a OpcLabs.EasyOpc.UA.UAStatusCodeException, a "Good" status code will be returned as the outcome of the OPC UA write operation. If the write value action function throws OpcLabs.EasyOpc.UA.UAStatusCodeException, the OpcLabs.EasyOpc.UA.UAStatusCodeException.StatusCode of the exception will become the outcome of the OPC UA write operation. For performance reasons, however, if you want to return status codes other than "Good" as OPC UA write operation outcomes, it is recommended that you use one of the WriteValueFunction<TValue>(UADataVariable,Type,Func<TValue,UAStatusCode>) method overloads instead. With these methods, you specify a write value function that returns the OpcLabs.EasyOpc.UA.UAStatusCode that is the OPC UA write operation outcome, allowing the status code be passed without the ineffective throwing and catching of the OpcLabs.EasyOpc.UA.UAStatusCodeException.