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
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)
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.
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[0]/nodeId/identifierType
- operations[0]/nodeId/namespaceIndex
- operations[0]/nodeId/identifier
- operations[0]/operationType READ
- operations[1]/nodeId/identifierTyp
- operations[1]/nodeId/namespaceIndex
- operations[1]/nodeId/identifier
- operations[1]/operationType READ
Note: The specific values are NOT defined here!
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.
For now, only the complete unformatted JSON will be returned.