Umati - OPC UA for Machine Tools (umati) MachineTool model

Layer: L7-Application · Flags: PC_ENABLE_OPCUA + PC_ENABLE_UMATI

Turns the board into a umati machine-tool server. umati ("universal machine technology interface", VDW / OPC Foundation, OPC 40501-1) is the OPC UA companion specification for machine tools: it standardizes how a machine reports its identity and live state so any umati / OPC UA client reads the same structure across every vendor. This example exposes that model over OPC UA on TCP/4840.

What it exposes

A MachineTool object under the Objects folder, with the standard umati components (faithful BrowseNames per OPC 40501-1):

MachineTool
  Identification   Manufacturer, Model, SerialNumber, YearOfConstruction, SoftwareRevision,
                   ProductInstanceUri
  Monitoring
    MachineTool    OperationMode, PowerOnDuration
    Channel        ChannelState, FeedOverride, RapidOverride, ActiveProgram
    Spindle        RotationSpeed, OverrideValue, IsRotating
    Axis_X/Y/Z     ActualPosition
  Production       ActiveProgram, ProducedPartCount
  Notification     ActiveMessage, Severity

You fill a UmatiMachineTool struct and refresh its live fields each loop() from your machine I/O; the server reads straight out of it. pc_umati_install(&mt) binds the struct and registers the OPC UA Browse + Read resolvers - that is the whole wiring.

What you teach

One companion-spec model, one struct. The values carry the standard umati BrowseNames, so a generic OPC UA client discovers and reads them the same way it would on a real CNC. It is a read-only monitoring model (the machine reports, the client observes), built on the OPC UA Binary server from example OpcUa.

Configure and flash

1. Set SSID / PASSWORD at the top of Umati.ino.
2. Build with both flags set (already in build_opt.h for the Arduino IDE):

   pio ci examples/L7-Application/Umati --board esp32dev --lib "." \
     --project-option="build_flags=-DPC_ENABLE_OPCUA=1 -DPC_ENABLE_UMATI=1"

3. Flash, open Serial @115200, note the IP.

Verify with an OPC UA client

Any OPC UA client works. With python asyncua:

import asyncio
from asyncua import Client
 
async def main():
    async with Client("opc.tcp://<BOARD_IP>:4840") as c:
        objects = c.nodes.objects
        for machine in await objects.get_children():          # MachineTool
            print("Machine:", await machine.read_browse_name())
            for comp in await machine.get_children():          # Identification / Monitoring / ...
                print(" ", await comp.read_browse_name())
 
asyncio.run(main())

Browse from Objects to MachineTool, then into Monitoring -> Spindle -> RotationSpeed and read it a few times - it tracks the simulated machine. UaExpert and the umati dashboard browse the same tree.

Scope

A single Channel / Spindle and three linear axes are exposed (the common embedded machine). The values are faithfully named per OPC 40501-1; full companion-spec TypeDefinitions and advertising the MachineTool namespace in the server's NamespaceArray (which needs array-Variant support in the base OPC UA server) are a documented follow-on - a generic OPC UA client still browses the structure and reads every value by BrowseName today.