Testing Guide

Practical test scenarios organized by OPC UA feature. Each scenario lists the server to use, what to do, and what to expect.

1. Connection & Session

Basic connection (no security)

• Server: opcua-no-security (4840)
• Steps:
  1. Connect to opc.tcp://localhost:4840/UA/TestServer
  2. Create a session (anonymous)
  3. Browse root -> Objects -> TestServer
• Expect: Session created, browse returns TestServer with sub-folders

Encrypted connection

• Server: opcua-userpass (4841)
• Steps:
  1. Discover endpoints via GetEndpoints()
  2. Select the Basic256Sha256/SignAndEncrypt endpoint
  3. Present client certificate and key
  4. Create session with username admin / admin123
• Expect: Encrypted session, full access

Connection rejection

• Server: opcua-userpass (4841)
• Steps:
  1. Try connecting without credentials (anonymous)
• Expect: BadIdentityTokenRejected

2. Reading & Writing

Read all data types

• Server: opcua-no-security (4840)
• Steps:
  1. Read all 21 variables under DataTypes/Scalar
  2. Verify each value matches the documented initial value
  3. Verify each DataType attribute matches the expected type
• Expect: All reads succeed with Good status

Write and read-back

• Server: opcua-no-security (4840)
• Steps:
  1. Write false to DataTypes/Scalar/BooleanValue
  2. Read it back
  3. Verify value is false
  4. Repeat for each data type with an appropriate test value
• Expect: All writes succeed, read-back matches written value

Write to read-only variable

• Server: opcua-no-security (4840)
• Steps:
  1. Write 42 to DataTypes/ReadOnly/Int32_RO
• Expect: BadNotWritable status code

Batch read

• Server: opcua-no-security (4840)
• Steps:
  1. Build a read request with all 21 scalar variables
  2. Send as a single Read service call
• Expect: 21 results, all Good

Array operations

• Server: opcua-no-security (4840)
• Steps:
  1. Read DataTypes/Array/Int32Array -> [-100000, -1, 0, 1, 100000]
  2. Write [1, 2, 3] (shorter array)
  3. Read back -> [1, 2, 3]
  4. Read an empty array -> []
  5. Write elements to an empty array, read back

3. Subscriptions & Monitored Items

Basic data change subscription

• Server: opcua-no-security (4840)
• Steps:
  1. Create subscription (publishingInterval = 1000)
  2. Add Dynamic/Counter as monitored item
  3. Wait for notifications
• Expect: One notification per second, value incrementing by 1

Fast data changes

• Server: opcua-no-security (4840)
• Steps:
  1. Create subscription (publishingInterval = 200)
  2. Monitor Dynamic/FastCounter with samplingInterval = 100
• Expect: ~5 notifications/second

Deadband filtering

• Server: opcua-no-security (4840)
• Steps:
  1. Monitor Dynamic/SineWave with absolute deadband of 0.5
  2. Count notifications over 30 seconds
• Expect: Fewer notifications than without deadband (~12 instead of ~30)

Multiple monitored items

• Server: opcua-no-security (4840)
• Steps:
  1. Create one subscription
  2. Add 5 dynamic variables as monitored items
  3. Verify notifications arrive for all 5
• Expect: Interleaved notifications from all monitored items

4. Method Calls

Simple method

• Server: opcua-no-security (4840)
• Steps:
  1. Call Methods/Add with a=2.5, b=3.5
• Expect: Output result = 6.0

Method with no input

• Server: opcua-no-security (4840)
• Steps:
  1. Call Methods/GetServerTime with empty input arguments
• Expect: Output time is a DateTime close to current time

Method failure

• Server: opcua-no-security (4840)
• Steps:
  1. Call Methods/Failing
• Expect: StatusCode BadInternalError

Method timeout

• Server: opcua-no-security (4840)
• Steps:
  1. Call Methods/LongRunning with durationMs = 10000
  2. Set client timeout to 5000ms
• Expect: Client-side timeout before method completes

Array input method

• Server: opcua-no-security (4840)
• Steps:
  1. Call Methods/ArraySum with values = [1.0, 2.0, 3.0, 4.0]
• Expect: Output sum = 10.0

5. Events

Subscribe to server events

• Server: opcua-no-security (4840)
• Steps:
  1. Create subscription on the Server node
  2. Add event monitored item with select: [EventType, Message, Severity, Time]
  3. Wait 2 seconds
• Expect: Receive SimpleEventType event with "Periodic event #N"

Trigger event via method

• Server: opcua-no-security (4840)
• Steps:
  1. Subscribe to events
  2. Call Methods/GenerateEvent("Test event", 750)
• Expect: Receive event with message "Test event" and severity 750

Filter events

• Server: opcua-no-security (4840)
• Steps:
  1. Subscribe to events with ContentFilter where Severity >= 500
  2. Wait for SystemStatusEventType in Maintenance state
• Expect: Only receive events with severity 600 (Maintenance)

6. Alarms

Monitor alarm transitions

• Server: opcua-no-security (4840)
• Steps:
  1. Subscribe to events on Alarms folder
  2. Wait for AlarmSourceValue to oscillate
• Expect: Receive alarm condition events as value crosses thresholds

Manual alarm trigger

• Server: opcua-no-security (4840)
• Steps:
  1. Write 100.0 to Alarms/AlarmSourceValue
  2. Check HighTemperatureAlarm state
• Expect: Alarm is active in HighHigh state

Acknowledge alarm

• Server: opcua-no-security (4840)
• Steps:
  1. Trigger an alarm (write extreme value)
  2. Read alarm's EventId
  3. Call Acknowledge method
  4. Verify AckedState is true

7. Historical Data

Read raw history

• Server: opcua-no-security (4840)
• Steps:
  1. Wait 30 seconds after server start
  2. HistoryRead Historical/HistoricalTemperature with ReadRawModifiedDetails
  3. Time range: last 30 seconds
• Expect: ~30 samples (recorded at 1000ms intervals), values oscillating around 22

Paginated history read

• Steps:
  1. Set NumValuesPerNode = 10
  2. Read history
  3. Use ContinuationPoint to fetch next page
• Expect: First page has 10 values, continuation returns more

8. Security

All security policies

• Server: opcua-all-security (4843)
• Steps:
  1. Call GetEndpoints()
  2. Iterate through returned endpoints
  3. Connect with each policy/mode combination
• Expect: Successful connections for all valid combinations

Certificate rejection

• Server: opcua-certificate (4842)
• Steps:
  1. Connect with certs/self-signed/cert.pem
• Expect: BadCertificateUntrusted

Expired certificate

• Server: opcua-certificate (4842)
• Steps:
  1. Connect with certs/expired/cert.pem
• Expect: BadCertificateTimeInvalid

Legacy policies

• Server: opcua-legacy (4847)
• Steps:
  1. Connect with Basic128Rsa15 / SignAndEncrypt
  2. Connect with Basic256 / Sign
• Expect: Both succeed (but your client should ideally warn about deprecated policies)

9. Extension Objects

Read custom structured type

• Server: opcua-no-security (4840)
• Steps:
  1. Browse to ExtensionObjects/PointValue
  2. Read the value
• Expect: ExtensionObject with TypeId ns=3;i=3010, binary body containing {X: 1.5, Y: 2.5, Z: 3.5}

Write custom structured type

• Server: opcua-no-security (4840)
• Steps:
  1. Write a new TestPointXYZ value {X: 10.0, Y: 20.0, Z: 30.0} to ExtensionObjects/PointValue
  2. Read it back
• Expect: Value matches {X: 10.0, Y: 20.0, Z: 30.0}

Read-only extension object

• Server: opcua-no-security (4840)
• Steps:
  1. Read ExtensionObjects/RangeValue
  2. Attempt to write a new value
• Expect: Read returns TypeId ns=3;i=3011 with {Min: 0.0, Max: 100.0, Value: 42.5}, write returns BadNotWritable

10. Operation Limits

Read with node limit

• Server: opcua-no-security (4840) -- configured with OPCUA_MAX_NODES_PER_READ=5
• Steps:
  1. Build a Read request with 10 node IDs
  2. Send the request
• Expect: Server rejects or limits the request (max 5 nodes per read)

Write with node limit

• Server: opcua-no-security (4840) -- configured with OPCUA_MAX_NODES_PER_WRITE=5
• Steps:
  1. Build a Write request with 10 node IDs
  2. Send the request
• Expect: Server rejects or limits the request (max 5 nodes per write)

11. Browsing & Navigation

Recursive browse

• Server: opcua-no-security (4840)
• Steps:
  1. Start at Objects/TestServer
  2. Recursively browse all nodes
• Expect: ~300 total nodes discovered

Deep nesting

• Steps:
  1. Browse Structures/DeepNesting/Level_1
  2. Continue browsing deeper: Level_2, Level_3, ..., Level_10
  3. Read Depth at each level
• Expect: 10 levels, Depth values 1-10

Browse with view

• Steps:
  1. Get NodeId of OperatorView from Views folder
  2. Browse TestServer with that view
• Expect: Only Dynamic, Methods, Alarms visible

12. Access Control

Access level attributes

• Steps:
  1. Read accessLevel attribute (ID=17) of AccessControl/AccessLevels/CurrentRead_Only
  2. Read userAccessLevel attribute (ID=18)
• Expect: accessLevel = CurrentRead, userAccessLevel = CurrentRead

Role-based write protection

• Server: opcua-userpass (4841)
• Steps:
  1. Connect as viewer (viewer123)
  2. Try to write to AccessControl/OperatorLevel/Setpoint
• Expect: BadUserAccessDenied 3. Connect as operator (operator123) 4. Write to the same variable
• Expect: Good

All type/access combinations

• Steps:
  1. For each type in AccessControl/AllCombinations:
     • Read _RO variant -> Good
     • Write _RO variant -> BadNotWritable
     • Read _WO variant -> BadNotReadable
     • Write _WO variant -> Good
     • Read and write _RW variant -> both Good
• Expect: 32 variables, all behave as documented

13. Discovery

Find servers

• Server: opcua-discovery (4844)
• Steps:
  1. Call FindServers() on opc.tcp://localhost:4844
• Expect: List of registered servers (if any have registered)

Get endpoints

• Server: any server
• Steps:
  1. Call GetEndpoints() on the server endpoint
  2. Parse the response
• Expect: List of endpoint descriptions with security policy, mode, and auth tokens