WriteState Method (defined in Table 13) is used to change the state of the State Variable in an instance of the MDISDigitalOutObjectType. The WriteState operation applies to the object in the subsea system. Some systems will be able to report any errors immediately others will only be able to report that the operation was not refused. Clients are expected to monitor the State and ensure that the operation completed. If an error occurs after the Method has returned, a Fault flag shall be set and an appropriate FaultCode will be returned. The Fault (and FaultCode) will reset on the next successful WriteState Method invocation.

Method Declaration

WriteState (

[in] State Boolean

);

Table 13 – WriteState Method parameters

Argument	Description
State	Boolean indicator of the target state of the variable

Method result codes are defined as part of the Call Service (see OPC UA Services Part 4 – Services specification). They are described in Table 94 for ease of reference.

Comments

The WriteState Method will change the state of the State Variable. The Method will report if any error occurs while writing the state of the Object. Table 14 specifies the AddressSpace representation for the WriteState Method.

Table 14 - WriteState Method AddressSpace Definition

Attribute	Value
BrowseName	State
References		Node Class	BrowseName	DataType	TypeDefinition	Modelling Rule
HasProperty		Variable	InputArguments	Argument[]	PropertyType	Mandatory