Table 59 defines the parameters for the Service.

Table 59 – Write Service Parameters







Common request parameters (see 7.33 for RequestHeader definition).

nodesToWrite []


List of Nodes and their Attributes to write. This structure is defined in-line with the following indented items.



NodeId of the Node that contains the Attributes.



Id of the Attribute. This shall be a valid Attribute id. The IntegerId is defined in 7.19. The IntegerIds for the Attributes are defined in OPC 10000-6.



This parameter is used to identify a single element of an array, or a single range of indexes for arrays. The first element is identified by index 0 (zero). The NumericRange type is defined in 7.27.

This parameter is not used if the specified Attribute is not an array. However, if the specified Attribute is an array and this parameter is not used, then all elements are to be included in the range. The parameter is null or empty if not used.

A Server shall return a Bad_WriteNotSupported error if an indexRange is provided and writing of indexRange is not possible for the Node.



The Node’s Attribute value (see 7.11 for DataValue definition).

If the indexRange parameter is specified then the Value shall be an array even if only one element is being written.

If the SourceTimestamp or the ServerTimestamp is specified, the Server shall use these values. The Server returns a Bad_WriteNotSupported error if it does not support writing of timestamps.

A Server shall return a Bad_TypeMismatch error if the data type of the written value is not the same type or subtype of the Attribute’s DataType. Based on the DataType hierarchy, subtypes of the Attribute DataType shall be accepted by the Server. Servers may reject subtypes defined in newer specification versions than supported by the Server with Bad_TypeMismatch. For the Value Attribute the DataType is defined through the DataType Attribute. A ByteString is structurally the same as a one dimensional array of Byte. A Server shall accept a ByteString if an array of Byte is expected.

The Server returns a Bad_DataEncodingUnsupported error if it does not support the provided data encoding.

Simple DataTypes (see OPC 10000-3) use the same representation on the wire as their super types and therefore writing a value of a simple DataType cannot be distinguished from writing a value of its super type. The Server shall assume that by receiving the correct wire representation for a simple DataType the correct type was chosen. Servers are allowed to impose additional data validations on the value independent of the encoding (e.g. having an image in GIF format in a ByteString). In this case the Server shall return a Bad_TypeMismatch error if the validation fails.




Common response parameters (see 7.34 for ResponseHeader definition).

results []


List of results for the Nodes to write (see 7.39 for StatusCode definition). The size and order of the list matches the size and order of the nodesToWrite request parameter. There is one entry in this list for each Node contained in the nodesToWrite parameter.

diagnosticInfos []


List of diagnostic information for the Nodes to write (see 7.12 for DiagnosticInfo definition). The size and order of the list matches the size and order of the nodesToWrite request parameter. This list is empty if diagnostics information was not requested in the request header or if no diagnostic information was encountered in processing of the request.