OPC UA client
Collect data from PLCs, CNC machines, robots and software that offer an OPC UA server, with secure connections and browsing of the address space.
opcua_client
Many modern controllers and machines have an OPC UA server: SIMATIC S7-1500, Omron NJ/NX, CODESYS-based PLCs, CNC controls and robot controllers. PLCGateway's OPC UA client reads them with batched reads or subscriptions and lets you browse the server's address space to pick the values.
Security is handled for you: the client certificate is created on first use, untrusted server certificates can be trusted from the user interface, and the security mode and policy can be selected or chosen automatically. PLCGateway itself is also an OPC UA server, so data from many sources can be combined into one structured address space.
- Driver id
opcua_client- Connection
- opc.tcp · None / Sign / SignAndEncrypt
- Address browsing
- yes
- Writing
- yes
What PLCGateway reads and writes
- Variables by string, numeric, GUID or opaque NodeId
- Namespace URIs resolved at connect
- Polling with batched reads or subscriptions with monitored items
- Arrays, DateTime and LocalizedText
- Security None, Sign and SignAndEncrypt with current policies
- Anonymous or user name / password login
Address examples
| Address | Meaning |
|---|---|
ns=2;s=Line1.Motor1.Speed | String NodeId |
ns=3;i=1001 · i=2258 | Numeric NodeId |
nsu=urn:example;s=Tag | NodeId with namespace URI |
ns=1;g=… | GUID NodeId |
Controllers and devices
Equipment that is typically connected with this driver.
Siemens SIMATIC
S7-1500, S7-1200, S7-300, S7-400, S7-200, LOGO!
Learn more →Omron SYSMAC
NJ, NX, CJ2, CJ1, CS1, CP1
Learn more →CODESYS-based controllers
WAGO PFC200, ABB AC500, Modicon M262, Eaton XC300, Festo CPX-E, soft PLCs
Learn more →FANUC CNC
Series 0i-D / 0i-F, 30i / 31i / 32i / 35i-B, 16i / 18i / 21i
Learn more →Connect in a few steps
Add an OPC UA client device with the endpoint URL (opc.tcp://host:4840) and use the discovery button to list the security options.
Choose security mode, policy and login; add the PLCGateway client certificate to the server's trusted clients and trust the server certificate.
Browse the address space and add the variables as tags.
Use the values or share them again through PLCGateway's own OPC UA server, MQTT and REST.
Questions and answers
Is the connection encrypted?
Yes, with Sign or SignAndEncrypt and the policies Basic256Sha256, Aes128_Sha256_RsaOaep and Aes256_Sha256_RsaPss. The automatic mode chooses the most secure endpoint of the server.
What is the difference to the OPC UA server of PLCGateway?
The client reads other OPC UA servers; the server publishes all tags of PLCGateway, from every protocol, to MES, ERP, historians and cloud platforms.
Can it read thousands of nodes?
Yes. Reads are batched and subscriptions only transfer changed values, which keeps the load on the server low.
Connect your machines
Tell us which controllers you run; we show you PLCGateway with your own addresses.
Product and model names are trademarks of their owners. They are named only to show which equipment the drivers communicate with; PLCGateway is not affiliated with these companies.