x/opcuaRead Component: v0.28.0+ OPC UA Read component, used to read data from an OPC UA server. It can read data from a single node or multiple nodes.

Additional extension library required: rulego-components-iot (opens new window)

Configuration

Field	Type	Description	Default
server	string	OPC UA server address; supports ref:// to reuse a connection within the same chain	None
policy	string	Security policy, options include: None, Basic128Rsa15, Basic256, Basic256Sha256	None
mode	string	Communication mode, options include: None, Sign, SignAndEncrypt	None
auth	string	Authentication method, options: Anonymous, UserName, Certificate	Anonymous
username	string	Username (required when auth is UserName)	None
password	string	Password (required when auth is UserName)	None
certFile	string	Certificate file path (required when auth is Certificate)	None
certKeyFile	string	Private key file path (required when auth is Certificate)	None
points	array	Point list (standard read method); each item has name/addr/type, addr = OPC UA NodeID	None

Point Fields (points array element):

Field	Type	Description
name	string	Point name; used as Data.name in output
addr	string	OPC UA NodeID, e.g. ns=2;s=Temperature
type	string	Data type, unified enum BOOL/INT16/UINT16/INT32/UINT32/INT64/UINT64/FLOAT32/FLOAT64/STRING

Security Policy (policy) Options Meaning:

• None: No security policy is used.
• Basic128Rsa15: Uses basic 128-bit encryption and RSA15 signing.
• Basic256: Uses basic 256-bit encryption.
• Basic256Sha256: Uses basic 256-bit encryption and SHA256 signing.

Communication Mode (mode) Options Meaning:

• None: No mode is used.
• Sign: Message signing.
• SignAndEncrypt: Message signing and encryption.

Read Points (Standard Method): specified via the points configuration, where addr is the OPC UA NodeID. Format:

[
  {"name": "temp", "addr": "ns=2;s=Temperature", "type": "FLOAT32"},
  {"name": "humidity", "addr": "ns=2;s=Humidity", "type": "FLOAT32"}
]

Legacy Compatibility: you may also pass a NodeID list via the message payload msg.Data (kept for backward compatibility only; points is recommended). Format:

[
  "ns=3;i=1003",
  "ns=3;i=1005"
]

Relation Type

• Success: Execution is successful, the message is sent to the Success chain.
• Failure: Execution fails, the message is sent to the Failure chain.

Execution Result

The query result is reassigned to msg.Data and passed to the next node through the Success chain, format:

[
  {"name": "temp", "value": 25.3, "timestamp": 1721900000000000000, "error": ""}
]