OPC UA

OPC UA (OPC Unified Architecture) is the most widely supported industrial communication protocol in Fleetera. It provides secure, reliable access to data from PLCs, SCADA systems, DCS controllers, and other industrial equipment.

Endpoint format

OPC UA endpoints use the opc.tcp:// scheme:

opc.tcp://hostname:port/path

Examples:

opc.tcp://192.168.1.100:4840/UA/Server
opc.tcp://100.77.174.77:4840/UA/WindFarmSimulator
opc.tcp://localhost:4840

The default OPC UA port is 4840. The path component is optional and depends on the server configuration.

When creating a connector, the opc.tcp:// prefix is added automatically — you only need to enter hostname:port/path.

Security configuration

Security policies

The security policy determines the encryption algorithm used for communication:

Policy	Description
None	No encryption. Suitable for development and trusted networks only.
Basic128Rsa15	128-bit RSA encryption. Legacy compatibility.
Basic256	256-bit encryption. Moderate security.
Basic256Sha256	256-bit encryption with SHA-256 hashing. Recommended for production.
Aes128Sha256RsaOaep	AES 128-bit with RSA-OAEP. High security.
Aes256Sha256RsaPss	AES 256-bit with RSA-PSS. Maximum security.

Security modes

The security mode controls message integrity and confidentiality:

Mode	Integrity	Confidentiality	Description
None	No	No	No security applied to messages
Sign	Yes	No	Messages are digitally signed to prevent tampering
SignAndEncrypt	Yes	Yes	Messages are both signed and encrypted

Using None for both security policy and mode means communication is unencrypted. This is acceptable for development environments but not recommended for production deployments.

Certificate configuration

When using a security policy other than None, you need to provide X.509 certificates:

Field	Description
Certificate File Path	Path to the X.509 certificate file (PEM format) on the edge gateway
Private Key File Path	Path to the private key file (PEM format) on the edge gateway

These paths reference files on the edge gateway machine where the edge device service runs.

Authentication

OPC UA connectors support these authentication methods:

Method	Description
Anonymous	No credentials required. The server must allow anonymous connections.
Username/Password	Basic authentication with username and password credentials.
Certificate	X.509 certificate-based mutual authentication.

Credentials are stored securely and referenced via the connector's secret reference field.

Subscription settings

OPC UA subscriptions control how the edge gateway receives data updates from the server:

Parameter	Default	Min	Description
Publishing Interval (ms)	1000	100	How often the server sends data updates to the client
Keep Alive Count	10	1	Number of publishing intervals without data before a keep-alive is sent
Lifetime Count	100	1	Number of publishing intervals before the subscription expires if no activity

Lower publishing intervals provide more responsive data updates but increase network traffic. For most industrial applications, the default of 1000ms (1 second) is appropriate.

Node ID formats

OPC UA nodes are identified by node IDs. Fleetera supports all standard formats:

Format	Example	Description
Numeric	`ns=2;i=1001`	Namespace 2, numeric identifier 1001
String	`ns=2;s=ActivePower`	Namespace 2, string identifier "ActivePower"
GUID	`ns=2;g=12345678-1234-1234-1234-123456789012`	Namespace 2, GUID identifier
Opaque	`ns=2;b=base64data`	Namespace 2, byte-string identifier

String identifiers (ns=N;s=...) are the most common in practice.

Using with bindings

When binding variables to OPC UA data points, you specify the node ID of the OPC UA variable you want to read. The connector's data model shows all available data points with their node IDs, and you can run a discovery crawl to populate it from the server's address space.

OPC UA

On this page