Opcua Tap

Read OPC-UA servers (opc.tcp) — browse the node tree, read node values with datatype/timestamp/status, bounded sampling, server info, best-effort alarm/condition surfacing, and threshold/anomaly health. Use when the task names OPC-UA, an opc.tcp:// endpoint, or a SCADA/PLC gateway exposing OPC-UA. Routes to the ot-aiops MCP server. Read-only. Do NOT use for IT/network gear, Kubernetes, hypervisors, or backups; for Modbus/S7/Mitsubishi/MTConnect/MQTT use the sibling *-tap skills.

Read-only OPC-UA telemetry + problem surfacing via the ot-aiops MCP server. Preview — validated against an in-process asyncua simulator, NOT live SCADA.

When to use

• An OPC-UA server / PLC gateway (opc.tcp://host:4840), anonymous or user/pass.
• Discover the address space, read tags, sample a node, surface alarms.

When NOT to use (routing)

• Modbus → modbus-tap; Siemens S7 → s7-tap; Mitsubishi → mc-tap; CNC machine tools → mtconnect-tap; MQTT/Sparkplug/UNS → sparkplug-tap; Rockwell/Allen-Bradley EtherNet/IP → ethernetip-tap.
• Cross-protocol "why no data" / alarm-flood / tag-health → industrial-diagnostics; OEE / downtime / asset inventory → industrial-analytics.
• IT/network devices, Kubernetes, hypervisors, backups → not this tool.

Tools

Tool	Params	Returns
opcua_server_info	endpoint?	{state, product_name, namespaces[...]}
opcua_browse	node_id="i=85", endpoint?, depth=2	[{node_id, browse_name, node_class, depth, parent}]
opcua_read_node	node_id, endpoint?	{value, datatype, source_timestamp, status_code, good}
opcua_read_many	node_ids[], endpoint?	[{node_id, value, ...}]
opcua_subscribe_sample	node_id, endpoint?, samples=5, interval_ms=500, timeout_s=30	{collected, samples[...]} (bounded)
opcua_read_alarms	endpoint?, node_id="i=85", depth=4	{active_alarms[...], active_count}
opcua_read_history	node_id, endpoint?, start?, end?, max_points=1000	{supported, count, values:[{value, source_timestamp, status_code}]}
health_summary	endpoint?, node_ids[]?, thresholds?	{overall, counts, offenders[...]}
anomaly_scan	node_id, endpoint?, samples=20, interval_ms=200, sigma=3.0	{mean, stddev, outliers[...]}

opcua_read_history is OPC-UA Historical Access (HDA): raw historical values over a [start,end] ISO-8601 window (bounded). It returns {supported:false, note} gracefully when the server does not historize the node. For bounded change-of-value (only the changes, not every sample) use monitor_changes from industrial-analytics.

Example

opcua_read_node(node_id="ns=2;i=5", endpoint="line1") → {"value":85.0,"datatype":"Double","source_timestamp":"2026-06-28T10:00:00Z","good":true}

Setup

ot-aiops init (add an opcua endpoint) · ot-aiops doctor · ot-aiops mcp. Config: ~/.ot-aiops/config.yaml; secrets encrypted in secrets.enc, unlocked via OT_AIOPS_MASTER_PASSWORD.

Safety

Read-only. Cert/message security (Sign/Encrypt) is roadmap — only anonymous + user/pass are validated. Endpoint text is sanitized; secrets are never returned. Missing a feature? 缺功能提 issue/PR 欢迎留言.