Mc Tap

Read Mitsubishi MELSEC PLCs (三菱 Q/L/QnA/iQ-R/iQ-L) over the MC protocol (3E binary, pymcprotocol) — CPU type, word devices (D/W/R), bit devices (M/X/Y/B), and scattered random reads. A governed, MOC-gated word write exists but is OFF by default. Use when the task names Mitsubishi/MELSEC, a D/M/X/Y device, or plctype Q/L/iQ-R. Routes to the ot-aiops MCP server. For OPC-UA/Modbus/Siemens/ MTConnect/MQTT use the sibling *-tap skills; not for IT/network gear, Kubernetes, hypervisors, or backups.

Mitsubishi MC read-first telemetry via the ot-aiops MCP server, using pymcprotocol (pure Python, MELSEC 3E binary). Preview — validated against a mocked client, NOT live PLCs. Only the 3E frame is supported (1E/4E are not).

When to use

• A Mitsubishi Q/L/iQ-R/iQ-L PLC with an Ethernet module open for MC (host:5007).
• Read word/bit devices; check CPU type.

When NOT to use (routing)

• OPC-UA → opcua-tap; Modbus → modbus-tap; Siemens → s7-tap; CNC → mtconnect-tap; MQTT/UNS → sparkplug-tap; cross-protocol triage → industrial-diagnostics. IT/network/Kubernetes/hypervisor/backup → not this tool.

Read tools

Tool	Params	Returns
mc_cpu_status	endpoint?	{cpu_type, cpu_code, plctype}
mc_read_words	headdevice (e.g. "D100"), endpoint?, count=1	{words:[int,...]}
mc_read_bits	headdevice (e.g. "M0"), endpoint?, count=1	{bits:[bool,...]}
mc_read_many	endpoint?, word_devices[]?, dword_devices[]?	{words:[{device,value}], dwords:[...]}

Example: mc_read_words(headdevice="D100", count=8) → {"headdevice":"D100","count":8,"words":[10,20,30, ...]}

Write tool (HIGH risk · MOC · off by default)

mc_write_words(headdevice, values[], endpoint?, dry_run=true)

• OT-DANGEROUS. 未经授权勿对生产控制系统写入. Defaults to dry_run=true. Captures BEFORE values (read-back of the range) and records an undo descriptor.
• Apply: dry_run=false + OPCUA_AUDIT_APPROVED_BY. CLI: ot-aiops mc write-words D100 1 2 3 --apply (double-confirm prompt).
• Dry-run → {dry_run:true, before, would_write, note}; applied → {applied:true, before, written, _undo_id}.

Setup

ot-aiops init (mc: host/port/plctype) · ot-aiops doctor · ot-aiops mcp. plctype ∈ Q | L | QnA | iQ-R | iQ-L. 缺功能提 issue/PR 欢迎留言.