Machinetalk is the middleware behind the Machinekit open source motion control software. Compared to other middleware approaches, Machinetalk is based on de-facto standard technologies instead of custom solutions to common problems. Machinetalk combines Protocol Buffers, ZeroMQ and DNS-SD over Multicast to one single bundle. The talk can be viewed at https://www.youtube.com/watch?v=8qzKLiO2chU For more information visit https://machinekoder.com/ and http://www.machinekit.io/.

1. Machinekit
CurrentStatusofMachinetalk
Alexander Rössler

2. 2
Overview
● Machinetalk Quick Intro
● Use in Machinekit
● Machinetalk GSL
● Machinetalk Generic
● Pymachinetalk

3. 3
Whatis Machinetalk?

4. 4
Machinetalk
● Middleware
● Component Component↔
● RT Userland↔
● Local Remote↔
Application Application
Middleware
API
Platform
Technology
API
Communication
Middleware
API
...
...

5. 5
UseCase 1–Multi UI
Single-Board
Computer
User Interface 1
User Interface 2
Machine Tool

6. 6
UseCase 2–MultiControl
Single-Board
Computer
Machine Tool
Workstation
Single-board
Computer
Machine Tool

7. 7
UseCase 3–InternalandExternal
Single-Board
Computer
Workstation
Smart Device
Remote
Pendant
GCode
Interpreter
Task
Controller
Motion
Controller
HAL
Web UI
Web
Bridge
Machine Tool

8. 8
Parts
Machinetalk
ZeroMQ
Protobuf
DNS-SDovermDNS
OS, Platform Technology
Protocol
Components
Transport / Messaging
Serialization
Service Discovery
Services

9. 9
Howis Machinetalk
used inmachinekit?

10. 10
Scope
Remote UI
API
HALHaltalk
Local UI
API
Motion
Controller
API
Trajectory
Planner
Client 1
Real-Time Environment
Real-Time Host 1
Task
Executor
GCode
Interpreter
Webtalk
Bridge
Client 2
MTMT
MTMTMTMT
ZeroMQ
Protobuf
Ring Buffers
Real-Time Host 2
Real-Time Environment
API
HAL
Userspace
Application
Fieldbus
Client 3
Web App
RB
RB
RB
RB
Websockets
JSON/Protobuf
WTWT
Protobuf

11. 11
Services & Components
Component Services
Haltalk halrcmd, halrcomp, (halgroup)
msgd log
mklauncher launcher, launchercmd
configserver config
mkwrapper status, command, error, file
previewmodule preview, previewcmd

12. 12
Close Up
Application
HAL Remote
Component
Client
Remote
Component
HAL Instance
Real-Time Environment
Real-Time Host
Haltalk
HAL Remote
Component
halrcmd
halrcomp
ZeroMQ
Protobuf
API

13. 13
WhataboutNML?
● Replace with Machinetalk
→ not completed
● Major refactoring of the CNC Stack

14. 14
What’s the dealwith
Machinetalk GSL?

15. 15
Reasons
● Not only Protobuf + ZMQ + DNS-SD/mDNS
● Knowledge embedded in code
● Repetitive across languages
● Protocols better formalized
● Protobuf Messages↔

16. 16
Imatix/GSL
● Model Oriented Programing
● Control Model + Generator
XML Model
.xml
GSL
Interpreter
Generated
Code
.cpp, .py, ...
GSL Template
.gsl

17. 17
Example

18. 18
HalremoteinFSMs
down
trying
Start
[Start]
/ Start Socket
/ Reset Heartbeat Liveness
/ Send Ping
/ Start Heartbeat Timer
Stop
[Stop]
/ Stop Heartbeat Timer
/ Stop Socket
up
Any Msg Received
[* Msg Received]
/ Reset Heartbeat Liveness
/ Reset Heartbeat Timer
Stop
[Stop]
/ Stop Heartbeat Timer
/ Stop Socket
Heartbeat Timeout
[Heartbeat Timeout]
/ Stop Socket
/ Start Socket
/ Reset Heartbeat Liveness
/ Send Ping
Heartbeat Timeout
[Heartbeat Timeout]
/ Stop Socket
/ Start Socket
/ Reset Heartbeat Liveness
/ Send Ping
Heartbeat Tick
[Heartbeat Tick]
/ Send Ping
Any Msg Sent
[* Msg Sent]
/ Reset Heartbeat Timer
Heartbeat Tick
[Heartbeat Tick]
/ Send Ping
Any Msg Received
[* Msg Received]
/ Reset Heartbeat Liveness
Any Msg Sent
[* Msg Sent]
/ Reset Heartbeat Timer
down
entry / Set Disconnected
exit / Set Connecting
trying
Connect
[Start]
/ Add Pins
/ Start Halrcmd Channel
Disconnect
[Stop]
/ Stop Halrcmd Channel
/ Stop Halrcomp Channel
/ Remove Pins
bind
Halrcmd Up
[Halrcmd State Up]
/ Bind Component
binding
Halrcomp Bind Msg Sent
[Halrcomp Bind Msg Sent]
syncing
No Bind
[No Bind]
/ Start Halrcomp Channel
Disconnect
[Stop]
/ Stop Halrcmd Channel
/ Stop Halrcomp Channel
/ Remove Pins
Halrcmd Trying
[Halrcmd State Trying] Bind Confirmed
[Halrcomp Bind Confirm Msg Received]
/ Start Halrcomp Channel
error
entry / Set Error
Bind Rejected
[Halrcomp Bind Reject Msg Received]
/ Stop Halrcmd Channel
Disconnect
[Stop]
/ Stop Halrcmd Channel
/ Stop Halrcomp Channel
/ Remove Pins
Halrcmd Trying
[Halrcmd State Trying]
/ Stop Halrcomp Channel
Sync Failed
[Halrcomp Error Msg Received]
/ Stop Halrcomp Channel
/ Stop Halrcmd Channel
synced
entry / Set Connected
Halrcomp Up
[Halrcomp State Up]
Disconnect
[Stop]
/ Stop Halrcmd Channel
/ Stop Halrcomp Channel
/ Remove Pins
Disconnect
[Stop]
/ Stop Halrcmd Channel
/ Stop Halrcomp Channel
/ Remove Pins
Halrcmd Trying
[Halrcmd State Trying]
/ Stop Halrcomp Channel
/ Unsync Pins
/ Set Timeout
Halrcomp Trying
[Halrcomp State Trying]
/ Unsync Pins
/ Set Timeout
Set Rejected
[Halrcomp Set Reject Msg Received]
/ Stop Halrcomp Channel
/ Stop Halrcmd Channel
Halrcomp Set Msg Sent
[Halrcomp Set Msg Sent]
down
trying
Start
[Start]
/ Start Socket
Stop
[Stop]
/ Stop Heartbeat Timer
/ Stop Socket
up
Full Update Received
[Full Update Msg Received]
/ Reset Heartbeat Liveness
/ Start Heartbeat Timer
Stop
[Stop]
/ Stop Heartbeat Timer
/ Stop Socket
Heartbeat Timeout
[Heartbeat Timeout]
/ Stop Heartbeat Timer
/ Stop Socket
/ Start Socket
Heartbeat Tick
[Heartbeat Tick]
/ Reset Heartbeat Timer
Any Msg Received
[* Msg Received]
/ Reset Heartbeat Liveness
/ Reset Heartbeat Timer

19. 19
Layering
Channel Layer
Implementation Layer
Subscriber RpcClient
«abstract»
RemoteComponentBase
RemoteComponent
Composition Layer
Model

20. 20
CodeGeneration
ProtosProtos
Protocol
Model
Component
Model
Code
Generator
ProtoBuf
Compiler
uses
Base
Class
Message
Classes
Message
GSL
Template
Protos
Component
Class

21. 21
Addinga newLanguageBinding
● Find libs
● Write MVP
● Build a code generator
● Implement details
Find
Requirements
Proof of
Concept
Generalize
1. 2. 3.
Specialize
4.

22. 22
GSLConclusion
● Perfect for protocols
● Less repetitive
● Focus on good models
● Consistency across languages

23. 23
Applications
● QtQuickVcp
● pymachinetalk
● WebVCP (webtalk-ng)
● node-machinetalk (not in production)

24. 24
More
● Formal Verification - UPPAAL
● SCXML support

25. 25
Canweuse
Machinetalkforother
applications?

26. 26
Machinetalk Generic
● Generalizes
– machinetalk-protobuf
– machinetalk-gsl
● multiple “Machinetalks” can live side-by-side
● Adds project namespace/package
● Generate client and server base

27. 27
Howtouse
● Fork machinetalk-protobuf
● Fork machinetalk-gsl
● Change/add project name alias
● Implement your protocols
● Define your message structure
● Generate
● Implement

28. 28
Whatisthe current
status of
pymachinetalk?

29. 29
Update
● Continued work
● Implemented mt-gsl
● Replaced avahi with zeroconf
● Easier to use serivce discovery
● Available via PyPI

30. 30
Example
import time
from pymachinetalk.dns_sd import ServiceDiscovery
import pymachinetalk.halremote as halremote
sd = ServiceDiscovery()
rcomp = halremote.RemoteComponent('anddemo', debug=False)
rcomp.newpin('button0', halremote.HAL_BIT, halremote.HAL_OUT)
rcomp.newpin('button1', halremote.HAL_BIT, halremote.HAL_OUT)
led_pin = rcomp.newpin('led', halremote.HAL_BIT, halremote.HAL_IN)
sd.register(rcomp)
sd.start()
try:
while True:
if rcomp.connected:
print('LED status %s' %s str(led_pin.value)
time.sleep(0.5)
except KeyboardInterrupt:
pass
sd.stop()

31. 31
Questions?