Sinumerik 840D 828D OPC UA Telemetry: Create MyHMI API Access

Reading Telemetry from Sinumerik 840D sl and 828D: OPC UA and Create MyHMI /3GL

Siemens Sinumerik 840D sl and 828D CNCs expose operating data, axis states, program information, and event timestamps through multiple read-only interfaces. This guide covers the two primary telemetry paths: the OPC UA server embedded in the NCU and the Create MyHMI /3GL programming package (C++ and .NET APIs). Both paths target the same control data, but they differ in deployment, performance, and integration footprint.

1. Sinumerik Architecture Relevant to Data Retrieval

Before selecting an API, map the data sources. A 840D sl / 828D installation typically exposes the following data origins:

All four data origins are reachable through the OPC UA server when the appropriate options are licensed. The Create MyHMI /3GL APIs reach the same nodes through the internal Operate component bus, but with a managed .NET or C++ interface.

2. Prerequisites

1. Hardware: NCU 710.3 / 720.3 / 730.3 (840D sl) or PPU 290.3 / 291.3 / 292.3 (828D). Older NCU 710/720 (without .3) are not OPC UA-capable and require the Create MyHMI path only.
2. Firmware: SINUMERIK Operate / NCU software version 4.95 SP2 or higher for OPC UA server. Version 4.08 or higher of Create MyHMI /3GL (ReleaseNotes_CreateMyHMI_3GL_V04.08.02 is the latest publicly mirrored revision).
3. Licensing: Option 6FC5800-0AP67-0YB0 (P67, "SINUMERIK OPC UA Server") must be activated on the CF card license file. Create MyHMI /3GL additionally requires 6FC5800-0AS12-0YB0 (Create MyHMI).
4. Network: NCU on a routable subnet; the OPC UA endpoint is bound to the X120 (840D sl company network) or X130 (828D) by default. Firewall rules: outbound TCP/4840 (default) or TCP/4841 (if TLS enabled).
5. Development tools: Visual Studio 2017 or higher for the .NET path, Visual C++ 2017 or higher for the C++ path, plus a UA-.NET-Standard or UA-.NET-Legacy SDK if you are building a custom client (Siemens does not redistribute a generic UA stack inside the /3GL package).

3. OPC UA Server: Activation and Address Space

3.1 Enabling the OPC UA Server

Activating the server is a two-step operation: license enablement in the CF card license file, then runtime configuration through the HMI.

1. Insert the P67 license on the CF card. Verify in Commissioning → Licenses on SINUMERIK Operate. The line "SINUMERIK Integrate OPC UA Server" must show status set.
2. Open the Commissioning menu, navigate to OPC UA configuration, and set the endpoint to opc.tcp://<NCU-IP>:4840 for unencrypted, or opc.tcp://<NCU-IP>:4841 for OPC UA Binary with TLS 1.2 (recommended for production).
3. Generate or import a server certificate (self-signed is acceptable for one-machine deployments; use a CA-signed certificate for multi-site OEE rollouts).
4. Create at least one user in User administration → OPC UA with the ReadTelemetry role. Anonymous read access is supported but should be disabled on connected systems.
5. Restart the OPC UA service: HMI menu Commissioning → OPC UA → Restart service, or NCK command pi/ ncu opcua_restart.

3.2 Address Space Layout

The Sinumerik OPC UA server publishes nodes in a hierarchical namespace. The top-level structure is consistent across 840D sl and 828D:

For statistical/operational data, the most relevant paths are:

• ns=4;s=Sinumerik/Nck/OperatingTimes/PowerOnTime — total power-on hours.
• ns=4;s=Sinumerik/Nck/OperatingTimes/ControlRunTime — total time the NC was in Run/Automatic/Manual.
• ns=4;s=Sinumerik/Nck/OperatingTimes/AxisTraverseTime[1..31] — per-axis motion time.
• ns=4;s=Sinumerik/Events/Alarms/History — alarm event history with timestamp (server-side) and payload (alarm number, clear text, channel).
• ns=4;s=Sinumerik/Plc/Var/DB<NNN>.DBW<X> — direct read access to PLC data blocks.

Use a generic OPC UA browser (UaExpert, Siemens OPC Scout) to confirm node availability on your specific firmware version. The node count and naming evolve between major firmware releases; always check the Diagnostics → OPC UA → Node list HMI view before wiring up a client.

3.3 Sample OPC UA Client (C#, UA-.NET-Standard)

The following snippet demonstrates a read with subscription for alarm events. It uses the official OPC Foundation UA-.NET-Standard library (not bundled with Sinumerik):

using Opc.Ua;
using Opc.Ua.Client;

var config = new ApplicationConfiguration {
    ApplicationName = "SinumerikTelemetryClient",
    ApplicationType = ApplicationType.Client,
    SecurityConfiguration = new SecurityConfiguration {
        AutoAcceptUntrustedCertificates = true   // demo only - replace with store in production
    },
    ClientConfiguration = new ClientConfiguration()
};
await config.ValidateAsync(ApplicationType.Client);

var endpoint = CoreClientUtils.SelectEndpoint(
    "opc.tcp://192.168.214.1:4840", useSecurity: false, 1500);
var session = await Session.Create(config, endpoint, false,
    "TelemetryClient", 60000, null, null);

// One-shot read: total operating hours
var opHours = session.ReadValue("ns=4;s=Sinumerik/Nck/OperatingTimes/ControlRunTime");
Console.WriteLine($"Control run time (s): {opHours.Value}");

// Subscription: alarm history
var subscription = new Subscription(session.DefaultSubscription) {
    PublishingInterval = 500
};
var item = new MonitoredItem {
    StartNodeId = new NodeId("ns=4;s=Sinumerik/Events/Alarms/History"),
    AttributeId = Attributes.Value,
    MonitoringMode = MonitoringMode.Reporting
};
item.Notification += (s, e) => {
    foreach (var v in e.NotificationValue.Value as EventFieldList[]) {
        // v.EventFields: [0]=EventId, [1]=SourceName, [2]=Time, [3]=Message, [4]=Severity
        var ts = (DateTime)v.EventFields[2].Value;
        var msg = (LocalizedText)v.EventFields[3].Value;
        Console.WriteLine($"[{ts:o}] ALARM {msg.Text}");
    }
};
subscription.AddItem(item);
session.AddSubscription(subscription);
subscription.Create();

4. Create MyHMI /3GL — C++ API

The Create MyHMI /3GL package (Siemens article ID 109955063) is a C++ component bus that runs inside the SINUMERIK Operate process. It exposes the same data sources as the OPC UA server, but through synchronous .so/.dll calls. Documentation is delivered as the PDF SINUMERIK Operate CPP:

• SINUMERIK Operate C++ Programming Manual
• Create MyHMI /3GL Release Notes V04.08.02

4.1 Component Highlights

• SlNck — read NCK variables, drive data, operating hours.
• SlPlc — read/write PLC variables (DB, Merker, Input/Output), with thread-safe access.
• SlHmi — query active channel, program name, operating mode.
• SlAlarm — subscribe to alarm queue and history.
• SlTool — read tool list, magazine assignment, life count.

4.2 Reading Operating Hours (C++)

#include "slnck.h"
#include "slhmi.h"

SlNckConnector* nck = SlNckConnector::instance();
if (!nck->connect("local", 5000)) {
    qCritical("NCK connection failed");
    return -1;
}

// Read control run time in seconds (BTSS variable)
qint64 runSec = 0;
SlNckVariable var("controlRunTime");
if (nck->readVariable(var, &runSec, sizeof(runSec))) {
    qInfo() << "Control run time (h):" << (runSec / 3600.0);
}

// Iterate per-axis traverse time
QStringList axes = nck->getAxisNames();
for (const QString& ax : axes) {
    qint64 t = 0;
    nck->readVariable(SlNckVariable("axisTraverseTime." + ax), &t);
    qInfo() << ax << "=" << (t / 3600.0) << "h";
}

5. Create MyHMI /3GL — .NET API

The .NET variant is targeted at C# or VB.NET applications running on the PCU/TCU/IPC alongside SINUMERIK Operate. See SINUMERIK Operate .NET Programming Manual for the full reference. Components are exposed as .NET assemblies under %ProgramFiles%\Siemens\Automation\SinumerikOperate\bin\3gl\ after installation.

5.1 C# Operating-Hours Read

using Siemens.Sinumerik.Operate._3GL;
using Siemens.Sinumerik.Operate._3GL.Nck;

using var nck = new SlNck();
nck.Connect("local", TimeSpan.FromSeconds(5));

var runTime = nck.ReadVariable<long>("controlRunTime");
Console.WriteLine($"Control run time: {runTime / 3600.0:F1} h");

// Subscribe to alarm history
var sub = nck.CreateAlarmSubscription(TimeSpan.FromMilliseconds(500));
sub.AlarmReceived += (s, e) => {
    Console.WriteLine($"[{e.Timestamp:o}] {e.Number} {e.Text}");
};
sub.Start();

6. Direct PLC DB Access

For custom machine telemetry stored in user PLC data blocks, both OPC UA and Create MyHMI /3GL can read directly. A typical DB mapping for an OEE tag is:

Reading DB120.DBD4 with the .NET API:

using Siemens.Sinumerik.Operate._3GL.Plc;
using var plc = new SlPlc();
float cycleTime = plc.ReadFloat("DB120.DBD4");

For the C++ API use slPlc.readFloat("DB120.DBD4") with the equivalent namespace include.

7. OPC UA vs. Create MyHMI: Selection Matrix

For greenfield OEE or SCADA projects, OPC UA is the default. For inline HMI extensions and runtime logic embedded in Operate, Create MyHMI /3GL is the lower-latency path.

8. Verification Procedure

1. Confirm license: HMI → Commissioning → Licenses shows OPC UA Server and (if applicable) Create MyHMI as set.
2. Open UaExpert (or equivalent) and connect to opc.tcp://<NCU-IP>:4840. Accept the server certificate, then authenticate with the configured user.
3. Browse the namespace. Verify Sinumerik/Nck/OperatingTimes/ControlRunTime exists and reports a value that increases when the NC is in Run.
4. Create a MonitoredItem on Sinumerik/Events/Alarms/History with a 500 ms publishing interval. Trigger a known alarm (e.g., remove an enable) and confirm the event is delivered with timestamp, alarm number, and clear text.
5. Read a PLC variable (e.g., DB120.DBD12) from both the OPC UA client and the /3GL .NET API. Values must match within one update interval.
6. Force a PLC stop and confirm the OPC UA server continues to deliver cached values and emits the expected ServerStatus_CommunicationFault event.
7. Capture an HMI screenshot of Diagnostics → OPC UA → Sessions showing the active client session and the configured security policy.

9. Troubleshooting Matrix

10. Security and Industrial Integration Notes

Both interfaces are intended to be integrated into a plant-wide industrial security concept. The Sinumerik Operate manual explicitly calls out that the automation and drive components must be embedded in a holistic, state-of-the-art industrial security concept for the plant or machine. Concretely:

• Restrict OPC UA endpoint to a private subnet; do not expose TCP/4840 or TCP/4841 to the office network.
• Use OPC UA with TLS 1.2 and a CA-signed certificate when crossing security zones.
• Disable anonymous authentication once the read clients are configured.
• Apply the latest SINUMERIK security patches; address space, role definitions, and certificate handling all change between releases.
• For multi-vendor OEE rollouts, prefer a UA wrapper (e.g., the Siemens Industrial Edge OPC UA Connector or a generic SCADA connector) rather than embedding Create MyHMI on the Operate host.

11. Additional Resources

• Siemens Industrial APIs and SDKs catalog
• Siemens API World overview
• SINUMERIK Operate C++ Programming Manual
• SINUMERIK Operate .NET Programming Manual
• Create MyHMI /3GL Release Notes V04.08.02