@synefex/node-red-lads 1.0.0
Node-RED nodes for LADS lab devices. Persistent OPC UA session, browse-based picker, full action set (read, write, call method, drive state machine).
@synefex/node-red-lads
Node-RED nodes for LADS lab devices. LADS (Laboratory and Analytical Device Standard) is the OPC UA companion spec for lab instruments. One persistent session per connection, an editor-side picker that browses the device tree, and four action nodes covering read, write, method call, and state-machine operate.
Install
In your Node-RED userDir (typically ~/.node-red/):
npm install @synefex/node-red-lads
Restart Node-RED. Five new nodes appear in the palette under the
Synefex LADS section.
Nodes
| Node | Purpose |
|---|---|
lads-connection |
LADS server connection, persistent session, auto-reconnect. Config node. |
lads-read-value |
Read the Value attribute of a node. |
lads-write-value |
Write a value with explicit data-type encoding. |
lads-call-method |
Call a method with input args and decoded outputs. |
lads-operate |
Drive the LADS FunctionalUnitState machine (Start, Stop, Abort, Hold, Resume, ...). |
Quick start
- Drop a LADS connection config node, point it at your server's
endpoint (
opc.tcp://host:port), and pick the right security mode/policy + auth combination for your server. - Wire an inject -> LADS read -> debug flow.
- Open the LADS read node. The picker (cascading dropdowns above the manual NodeId field) lets you browse Device -> Functional Unit -> Function -> Variable. Pick the variable you want.
- Deploy and click inject.
payloadbecomes the decoded value.
Picker
Open any LADS action node in the editor and the picker shows up above the manual fields:
- Device -- top-level LADS device (browsed from the connection)
- Functional Unit -- subsystem within a device (e.g. WeighingSensor)
- Function -- behavior within an FU (e.g. CurrentValue)
- Variable / Method -- the leaf you actually pick
The picker resolves to a NodeId and writes it into the manual NodeId field; the symbolic browse path is stored alongside for re-edit restoration. Picking writable variables also auto-fills the Data type dropdown on the write node.
Security
For lab devices on a trusted network, None / None / Anonymous is usually enough. Switch to Sign or Sign & Encrypt with a matching policy when the server requires it. Validated combinations:
- None / None / Anonymous
- Sign / Basic256Sha256 / Anonymous
- SignAndEncrypt / Basic256Sha256 / Anonymous
- SignAndEncrypt / Aes128_Sha256_RsaOaep / Anonymous
- SignAndEncrypt / Aes256_Sha256_RsaPss / Anonymous
- (and Username/Password variants of all of the above)
The first time a secured connection is attempted, a self-signed client
certificate is generated under <userDir>/lads-pki/own/certs/. The
server administrator may need to add it to the server's trust list
before the connection succeeds, or you can flip on Auto-trust server
certificate for lab/testing.