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Methods

Path: Objects > TestServer > Methods

12 callable methods covering arithmetic, string operations, arrays, async operations, error handling, and event generation.

Method Reference

Add

Adds two doubles.

Name DataType Description
Input a Double First operand
Input b Double Second operand
Output result Double a + b

Multiply

Multiplies two doubles.

Name DataType Description
Input a Double First operand
Input b Double Second operand
Output result Double a * b

Concatenate

Concatenates two strings.

Name DataType Description
Input a String First string
Input b String Second string
Output result String a + b

Reverse

Reverses a string.

Name DataType Description
Input input String Input string
Output result String Characters in reverse order

GetServerTime

Returns the current server time. No input arguments.

Name DataType Description
Output time DateTime Current server UTC time

Echo

Echoes back any value. Accepts a Variant (any OPC UA type) and returns it unchanged. Useful for testing type serialization round-trips.

Name DataType Description
Input input Variant Any value
Output output Variant Same value echoed back

GenerateEvent

Raises a BaseEventType event on the server object. Useful for testing event subscriptions on demand.

Name DataType Description
Input message String Event message text
Input severity UInt16 Event severity (0-1000)

No output. The event is raised asynchronously and can be received by any client subscribed to events on the server object.

LongRunning

Simulates a long-running operation. The method blocks for the specified duration, then returns.

Name DataType Description
Input durationMs UInt32 Duration in milliseconds (capped at 30,000)
Output completed Boolean Always true on completion

Testing notes:

  • The server caps the duration at 30 seconds to prevent abuse
  • Use this to test method call timeouts in your client
  • If your client has a 5-second timeout, call with durationMs = 10000 to trigger it

Failing

Always returns an error. No inputs, no outputs.

Name DataType Description
(none)

Returns: BadInternalError (0x80020000)

Testing notes:

  • Use this to verify your client correctly handles method call failures
  • The method call itself succeeds at the OPC UA transport level, but the result status code is BadInternalError

ArraySum

Sums all elements of a Double array.

Name DataType Description
Input values Double[] Array of doubles
Output sum Double Sum of all values

Testing notes:

  • Tests passing array arguments to methods
  • Try with empty array, single element, large arrays

MatrixTranspose

Transposes a flat matrix representation.

Name DataType Description
Input matrix Double[] Flat matrix data (row-major)
Input rows UInt32 Number of rows
Input cols UInt32 Number of columns
Output result Double[] Transposed matrix (flat, row-major)

If matrix.length != rows * cols, returns BadInvalidArgument.

Example:

Input:  matrix=[1,2,3,4,5,6], rows=2, cols=3
        Represents: [[1,2,3],[4,5,6]]
Output: result=[1,4,2,5,3,6]
        Represents: [[1,4],[2,5],[3,6]]

MultiOutput

Returns multiple output values of different types. No inputs.

Name DataType Description
Output intValue Int32 Always 42
Output stringValue String Always "hello"
Output boolValue Boolean Always true

Testing notes:

  • Verifies your client can handle multiple output arguments
  • Verifies correct type mapping for each output

Testing Checklist

  • Call Add(2.5, 3.5) -> expect 6.0
  • Call Multiply(3.0, 4.0) -> expect 12.0
  • Call Concatenate("Hello", " World") -> expect "Hello World"
  • Call Reverse("abcde") -> expect "edcba"
  • Call GetServerTime() -> expect a DateTime close to current time
  • Call Echo with various types (Int32, String, Boolean, Array) -> expect same value back
  • Call GenerateEvent("test", 500) -> verify event received on subscription
  • Call LongRunning(2000) -> expect true after ~2 seconds
  • Call LongRunning(60000) -> duration is capped to 30s
  • Call Failing() -> expect BadInternalError
  • Call ArraySum([1.0, 2.0, 3.0]) -> expect 6.0
  • Call MatrixTranspose([1,2,3,4], 2, 2) -> expect [1,3,2,4]
  • Call MatrixTranspose([1,2,3], 2, 2) -> expect BadInvalidArgument
  • Call MultiOutput() -> expect (42, "hello", true)