Call for READ operations  (the name READ is the arbitrarily chosen name for this call)

Input Parameter

For the READ Connector Call, you need to configure the “operationType ” and the “nodeId“(consisting of 2 mandatory parameters: “identifier” and “namespaceIndex”  and one optional parameter: “identifierType”). Furthermore, you can define the “order” of the operations in the code (optional).

 

operationType: Defines which operation you want to execute, in this case, “READ”.
Parameter Name: operations[0]/operationType
Constant Value: READ
Data Type: String

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nodeId: Defines the identification of the OPC UA node. It is split in 3 parameters (two mandatory and one optional):

• identifier:
  Parameter Name: operations[0]/nodeId/identifier
  Data Type: String
• namespaceIndex:
  Parameter Name: operations[0]/nodeId/namespaceIndex
  Data Type: String
  Possible Values: All numbers from 0 to 65535.
• identifierType (optional): Searches for the Identifier with a fixed Data Type.
  Parameter Name: operations[0]/identifierType
  Data Type: String
  Constant Value: Numeric, UUID, String, Byte String

Note: In every namespace, each ID must be unique for its own identifierType (it is possible to use the String “7617” and the Numeric 7167 together in one namespace)

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order (optional): Order in which the actions should be performed.
This parameter changes the execution order of the specified READ commands e.g. if we have three READ commands. Command 1 reads from node x, command 2 reads from node y and command 3 from node z, the normal execution order would be: x, y, z.

By specifying the read order with numbers starting from 0 to the last command number subtracted by one (e.g. for three commands it would be 2), the execution will be changed according to the defined number.

For example, by adding “order”:[2,1,0] to your code, you switched the operations, so the read commands would be executed the following way. z, x, y.

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Batch Operations

It is possible to execute multiple different OPC UA Operations with one connector call. In order to do that, the number in the operations[X] path must be used.  Each number represents one OPC UA Operation.

A batch call with two READ-Operations would look as follows (Only constant values are provided with bold letters):

First READ Operation:

• operations[1]/nodeId/identifierTyp
  
• operations[1]/nodeId/namespaceIndex
• operations[1]/nodeId/identifier
• operations[1]/operationType      READ

Note: The specific values are NOT defined here!

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Output parameters

You can return all Output Parameters like this:

Parameter Name: /
Data Type: String

If you want to get only selected Output Parameters, use the following syntax:

Parameter Name: operationsResult/[0]/dataType/name (exemplary)
Data Type: depends on the Parameter you want to be returned.

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For now, only the complete unformatted JSON will be returned.