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Tips & Best Practices for Exploration

This guide provides best practices for effective OPC UA address space exploration.

Start Small​

Begin with a specific node rather than the entire server:

✅ Good:

nodeId: "ns=2;s=Equipment.Reactor1"

❌ Avoid:

nodeId: "i=85"  // Objects folder - very large!

Use Appropriate Output Type​

Choose based on your needs:

// For monitoring: Use NodeId
outputType: "NodeId"

// For display: Use Value
outputType: "Value"

// For documentation: Use BrowsePath
outputType: "AliasedBrowsePath"

Cache Exploration Results​

Structure rarely changes - cache the results:

// Function node: Cache structure
const cacheKey = 'reactor1_structure';
const cached = flow.get(cacheKey);

if (cached && (Date.now() - cached.timestamp < 3600000)) {
    // Use cached (less than 1 hour old)
    msg.payload = cached.structure;
    return msg;
}

// Cache new result
flow.set(cacheKey, {
    timestamp: Date.now(),
    structure: msg.payload
});

return msg;

Validate Before Use​

Always check the structure exists:

// Function node: Safe access
const structure = msg.payload;

if (!structure || Object.keys(structure).length === 0) {
    node.error("Exploration returned no results");
    return null;
}

return msg;

Common Use Cases​

1. Generate Monitoring Configuration​

Explore equipment and create monitoring setup:

// Explore with NodeId output
msg.outputType = "NodeId";
// Result goes to Monitor node

2. Documentation Generation​

Create documentation of available data:

msg.outputType = "AliasedBrowsePath";
// Convert to markdown table

3. Dynamic Dashboard Creation​

Build UI based on available data:

msg.outputType = "Value";
// Create dashboard widgets dynamically

4. Data Discovery​

Find specific variables across the server:

// Function node: Find temperature variables
function findTemperatures(obj, path = '', result = []) {
    for (const [key, value] of Object.entries(obj)) {
        if (key.toLowerCase().includes('temp')) {
            result.push({
                name: key,
                path: path ? `${path}.${key}` : key,
                value: value
            });
        } else if (typeof value === 'object') {
            findTemperatures(value, path ? `${path}.${key}` : key, result);
        }
    }
    return result;
}

const temps = findTemperatures(msg.payload);
msg.payload = temps;
return msg;

Next Steps​

See Also​