Local network control
Connect through the Z21 LAN interface without routing train commands through a cloud service.
LocoLink · independent software for Roco/Fleischmann Z21
LocoLink for Z21.
Modern control on every screen.
LocoLink is the app; Z21 is the supported command station. Connect them over your local network to drive locomotives, switch accessories, build a track plan, program DCC decoders and grow into feedback-based automation.
Independent LocoLink softwareZ21 fully supportedLocal LAN connection
LocoLink + Z21The Z21 remains the digital command station; LocoLink is the independent control app and layout project.
Windows + ApplePlatforms
30 daysPro trial
NonePayment today
Z21 · ECoS · DCC-EXCore systems
“Making the hobby feel like it can keep up with modern technology is a joy. Whether it is asking Siri to 'stop Mallard' or using a PlayStation 5 controller — I constantly had a smile on my face.”★★★★★ App Store Review · United Kingdom Review evidence and repeatable test guide
Z21 workflow
Use the open network connection for more than driving
The Z21 family provides a strong base for app control. LocoLink adds a consistent project across Windows and Apple devices.
Locomotive throttle
Control speed, direction, emergency stop and decoder functions with a modern UI.
Track plan and routes
Operate turnouts and signals in the context of your complete layout.
DCC programming
Use supported Z21 programming workflows for CV reading, writing and speed tables.
Feedback and blocks
Bring supported feedback data into block control and automatic operation.
Project and import tools
Use structured project checks and supported Z21 data workflows when building the LocoLink project.
Setup
Connect LocoLink to Z21
Use the official Z21 network setup as the base and validate one locomotive before adding the complete layout.
Join the same network
Connect the device running LocoLink to the LAN or Wi-Fi network that contains the Z21.
Find or enter the Z21
Use Auto-scan or enter the local address. LocoLink pre-fills 192.168.0.111 and UDP port 21105; change the IP address if your network uses another one.
Test and expand
Confirm the connection, then try emergency stop, direction and one accessory before importing data or enabling automation.
Z21 family
Z21 details that affect app control
The product name on the box is not the only detail that matters.
| Item | What it means | Action |
|---|---|---|
| Black Z21 / Z21 XL | Network control is part of the platform | Connect on the same LAN and verify firmware |
| White z21 | Network app control is a core use case | Use the supported router/LAN configuration |
| z21 start | LAN control may be locked in a starter set | Check whether the official Z21 unlock package has been activated |
| Firmware | Protocol behaviour can improve over time | Update through official Z21 tools when appropriate and retest |
| Feedback hardware | Bus and module choice determines available events | Validate every sensor address before automation |
Compatibility reviewed . The official Z21 documentation is the authority for hardware activation and firmware. LocoLink publishes its own integration status in the command-station adviser.
Inside the real LocoLink app
See the actual Z21 connection workflow
These are LocoLink product screens, not a generic Z21 mock-up. The settings view exposes the Z21 address, UDP port, Connect action, setup wizard and Central Diagnostics before you operate the layout.
Choosing a Z21 app
Official Z21 app or an alternative control environment?
LocoLink is independently developed by Westerman. It is not the official Z21 App and is not a Roco/Fleischmann product. Z21 names the compatible command-station family; the software offered on this page is always called LocoLink.
The official Z21 app is the natural starting point for many Z21 owners and remains useful for supported Z21 workflows. LocoLink is an alternative for operators who want the same layout-oriented control environment on Windows, Mac, iPhone and iPad, with guided decoder, project and automation tools.
An alternative app does not change the electrical role of the Z21. The command station still talks to the decoders and provides the digital system. LocoLink connects through the documented local-network interface and adds its own project model and user experience.
Test before changing an exhibition or club layout
Keep the existing Z21 setup available, back up relevant projects and validate LocoLink on one route. Confirm that addresses, functions, accessory formats and feedback events match before enabling automatic operation.
If you own a z21 start, first verify the official LAN unlock status. An app cannot work around a command station that has not enabled third-party LAN control.
Compare the complete setup in the model train control software guide, use the British model railway control software guide and its focused model railway control phone app setup, or follow the computer-controlled model railway UK guide for staged commissioning. The German guide covers Modellbahnsoftware zur Steuerung. The DCC controller app guide explains how the app works with the command station and booster.
Comparing Z21 with the wider control category? Use the model train control app comparison. Choosing between control software, track planning, inventory and simulation first? Use the broad model train software guide.
Using a phone around the layout? Follow the locomotive control app for iPhone and iPad guide.
FAQ
Frequently asked questions
Does LocoLink work with Roco/Fleischmann Z21?
Yes. Roco/Fleischmann Z21 is fully supported over the local network.
Does a z21 start need an unlock code?
Some z21 start units supplied in starter sets require the official Z21 LAN unlock package before third-party app control is enabled.
Does LocoLink replace the official Z21 app?
It is an alternative control environment, not a requirement. You can evaluate both and choose the workflow that suits your layout.
Can LocoLink program decoders through Z21?
Supported Z21 programming workflows are available. Always use the correct programming track or POM setup and test with the exact firmware.
Can I automate a Z21 layout with LocoLink?
Yes, when feedback, blocks, routes and stopping behaviour are correctly configured and validated.
Is there a Z21 app for Windows or PC?
Yes. LocoLink is a native Windows model-train control app and fully supports Z21 over the local network, so no Android emulator is required.
Can I control Z21 from Mac, iPhone or iPad?
Yes. LocoLink is available for Mac, iPhone and iPad as well as Windows, with Z21 fully supported over the local network.
Is LocoLink free to try with Z21?
LocoLink is free to download and includes a 30-day Pro trial without payment today. Continued Pro use requires a paid plan after the trial.
Verification
Sources and review
Product and compatibility claims are checked against first-party documentation. Every listed command station is fully supported; direct, interface and gateway only describe the required connection route.
- LocoLink downloads and current platform availability LocoLink
- LocoLink command-station compatibility adviser LocoLink
- Z21 LAN Protocol Specification Roco / Fleischmann Z21
- Z21 manuals and technical downloads Roco / Fleischmann Z21