Controller · Siemens
Connect SINUMERIK 840D sl
SINUMERIK 840D sl has a native OPC UA server, enabled by the paid option Access MyMachine /OPC UA (order number 6FC5800-0AP67-0YB0) and reached at opc.tcp://<HMI-IP>:4840. It needs SINUMERIK Operate and a supported CNC software version (4.5, 4.07 SP2–SP5, 4.08 SP2–SP3 or 4.92). Without the option, gateways such as Softing uaGate 840D read the NC over the S7 protocol and serve OPC UA, with no extra Siemens runtime licence according to Softing.
At a glance
| Native protocol | OPC UA server (Access MyMachine /OPC UA) |
|---|---|
| Licence on the CNC | 6FC5800-0AP67-0YB0 (paid) |
| Port | TCP 4840 |
| Interface | X130 / X120 on NCU (thin client); eth1/eth2 with PCU/IPC |
| Security | Basic256Sha256 by default; anonymous off |
| Without the option | S7 gateway (uaGate 840D, IBH Link UA, dataFEED) |
Connection paths
Native OPC UA serverRecommended
Richest and cleanest: channel, spindle, alarms, tools, PLC, methods. Licensed per control.
S7/RFC1006 gatewayAlternative
Softing uaGate 840D / SDEX, IBH Link UA or dataFEED OPC Server CNC read the NC through the S7 protocol (port 102) and serve OPC UA/MQTT.
MTConnect adapterAlternative
Memex MERLIN adapter for 840D (requires a Siemens OA runtime licence).
Siemens cloud/edgeVendor product
Manage MyMachines (SINUMERIK Integrate client) and Industrial Edge for Machine Tools apps.
Licences and options
| Item | Option / part number | Paid? | Note |
|---|---|---|---|
| Access MyMachine /OPC UA | 6FC5800-0AP67-0YB0 | Paid | Activate under Startup > Licenses; may need a service technician |
| Run MyHMI (Operate OA runtime, for MTConnect adapters) | 6FC5800-0AP60-0YB0 | Paid | Required by the Memex MERLIN adapter |
| SINUMERIK Operate toolbox incl. NCVar Selector (for S7 gateways) | 6FC5851-1XC45-4YA8 | Paid | Used to generate symbol files for uaGate 840D |
Ports
| Port | Protocol | Note |
|---|---|---|
4840 | TCP | OPC UA server (configurable); opened automatically on the NCU, manually on PCU/IPC |
102 | TCP | S7 / RFC1006 used by gateways (open in the SINUMERIK firewall on X120/X130) |
Software versions
- CNC SW 4.5 → OPC UA server V2.2 and V3.0 SP1
- 4.07 SP2 to SP5 → V2.2 / V3.0 SP1
- 4.08 SP2 to SP3 → V2.2 / V3.0 SP1
- 4.92 and 4.92 HF2 → V3.0 SP1 only
- Softing uaGate 840D: 840D sl from software V2.7 (its FAQ narrows this to NCU 7x0.3 PN with software newer than V4.3)
Data you can read
- Channel state: execution state, operating mode, active program name, block, line
- Spindle: rotating, speed, load; feed rate and override
- Alarms: event-based NC, PLC and HMI alarms with multilingual texts (needs the AlarmRead right)
- R parameters, global user data (GUD) and NC variables by path, for example
/Channel/Parameter/R[u1,10] - PLC data:
/Plc/MB6,/Plc/DB5.DBW2, arrays such as/Plc/DB2.DBD0:REAL[10](828D: customer DBs from DB9000 only) - Tools: tool data, cutting edges, magazine; methods to create and delete tools and cutting edges
- Part counters (actual and total parts) and program selection (Select/Deselect methods with the ApWrite right)
Setting it up
- Check the licence and software versionAccess MyMachine /OPC UA must be licensed and activated: order number 6FC5800-0AP67-0YB0 for 840D sl and 828D. Check the CNC software version against the compatibility table below before you order.
- Use the right network interface828D: X130 (company network). 840D sl with thin client: X120 and X130 on the NCU. 840D sl with PCU or IPC: the server is reachable on eth1 and eth2 of the PC, not on X120/X130. Do not change the 192.168.214.x and 192.168.215.x system networks.
- Raise the access levelEnter the Manufacturer access level so the commissioning screens are available.
- Activate the serverStartup (Commissioning) > Network > OPC UA > Setting > Change. Choose the network (company, system or service), confirm IP address and port 4840, tick "Activate OPC UA", OK.
- Create a user and rightsAnonymous access is off by default and should stay off. Create a user with a strong password (8 or more characters, mixed case, digits, special characters) and give it only the rights it needs, for example StateRead, ToolRead, AlarmRead.
- RestartHardware restart of the NCU or PPU; on a PCU 50 or IPC, restart Operate.
- Exchange certificatesStartup > Network > OPC UA > Certificates. The server certificate is generated at first start (20-year validity). Import the client certificate (.der) and trust the HMI certificate on the client side. Switch off automatic certificate acceptance once commissioning is done.
- Verify with a generic clientConnect with UaExpert to
opc.tcp://<HMI-IP>:4840using Basic256Sha256 Sign & Encrypt, browse, read a channel state, then hand over to the production client.
Troubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
| BadCertificateTimeInvalid | System time wrong on the control or the client | Set the clock on both sides (NTP where possible), then reconnect. |
| BadSecurityChecksFailed | Client certificate not trusted by the server | Move the client certificate to the trusted list under Startup > Network > OPC UA > Certificates. |
| Endpoint not reachable on 840D sl with PCU | Client is dialling X120/X130 | With a PCU or IPC the server listens on eth1/eth2 of the PC; open TCP 4840 in the PC firewall. |
| Login works, every read is denied | New users have no rights | Grant the needed rights (StateRead, AlarmRead, ToolRead, PlcRead…) with the admin user. |
| 828D cannot read a PLC data block | 828D exposes customer data blocks from DB9000 only | Ask the PLC programmer to copy the values into a DB at or above DB9000. |
| Security None endpoint missing | Only 256-bit policies are active by default | Keep it that way in production; enable None only temporarily for a reachability test if your site policy allows it. |
Traps to avoid
- Custom object models (CSOM) built in SiOME: up to 7 custom namespaces and 10,000 nodes.
- Up to 149 parameters per array access.
- Event subscriptions through some middleware are polled instead, because notifications can affect server stability (Cybus guidance).
- Siemens does not publish a maximum number of clients or monitored items in the manual we checked: size the client conservatively.
Connectors that support this control
| Product | Vendor | Type | Outputs |
|---|---|---|---|
| uaGate 840D | Softing | Gateway | OPC UA (≤20,000 nodes), MQTT |
| edgeConnector (840D, FANUC CNC) | Softing | Gateway | OPC UA 1.04, MQTT 3.1/3.1.1/5 |
| SDEX Suite | Softing | Gateway | OPC UA, MQTT, REST |
| dataFEED OPC Server CNC | Softing | OPC server / driver | OPC DA; optional OPC UA 1.04, MQTT, REST |
| IBH Link UA | IBHsoftec | Gateway | OPC UA (incl. OPC 40502 CNC model), MQTT Sparkplug B |
| Connectware | Cybus | Edge platform | MQTT, OPC UA server |
| WebAccess/CNC | Advantech | Monitoring software | OPC UA/DA, Modbus, REST |
| MERLIN Tempus + MERLIN adapters | Memex | Monitoring software | MTConnect |
| Manage MyMachines | Siemens | Control or machine maker | Cloud (Insights Hub) |
| Industrial Edge for Machine Tools | Siemens | Control or machine maker | REST, MQTT |
| Kepware Server — Siemens TCP/IP Ethernet | Velotic (formerly PTC Kepware) | OPC server / driver | OPC UA, OPC DA |
| StateMonitor | HEIDENHAIN | Control or machine maker | ERP/MES job interface |
| Predator MDC | Predator Software | Monitoring software | SQL / MES / ERP |
| FactoryWiz Monitoring | FactoryWiz | Monitoring software | — |
Not published by the vendor. We could not find these in vendor documentation. Ask the control or machine maker before you rely on them.
- Maximum sessions and monitored items of the OPC UA server
- List price of 6FC5800-0AP67-0YB0 (shown only after login in the Siemens Industry Mall)
Questions engineers ask
How do I enable OPC UA on a SINUMERIK 840D sl?
License Access MyMachine /OPC UA (6FC5800-0AP67-0YB0), then Startup > Network > OPC UA > Setting > Change, tick Activate OPC UA, restart, and exchange certificates.
Can I read an 840D sl without the OPC UA licence?
Yes, with an S7-protocol gateway such as Softing uaGate 840D, IBH Link UA or Softing dataFEED; Softing states no additional Siemens licence is needed, though the NCVar Selector toolbox is used for symbols.
Which port does SINUMERIK OPC UA use?
TCP 4840 by default.
Related
Sources
Facts on this page come from these documents, opened on 27 October 2026.
- Siemens — SINUMERIK 840D sl/828D Access MyMachine/OPC UA configuration manual (08/2019)
- Siemens Industry Online Support forum — OPC UA licence
- MachineMetrics support — SINUMERIK OPC UA connectivity
- MachineMetrics support — Siemens 840D OPC UA option
- Softing — uaGate 840D
- Softing — uaGate 840D FAQ
- IBHsoftec wiki — IBH Link UA with SINUMERIK 840D / 840D sl
- Cybus — SINUMERIK connector
- Memex — MERLIN adapter for SINUMERIK 840D
- Siemens — Manage MyMachines system requirements
Last verified 27 October 2026 against vendor documentation. OPC UA Connect is an educational resource published by TEEPTRAK; it is not affiliated with the OPC Foundation, the MTConnect Institute or any control maker.