simulink-configure-real-time-target

Configuring Simulink Real-Time Targets

Manage target computer definitions for Simulink Real-Time — the development-computer records that name a target and store its IP and credentials — plus the ops that act on the target computer itself (connect, reboot, RTOS update, startup app).

Release compatibility: Designed and validated for MATLAB R2026a and later. Not recommended for earlier releases: APIs, system target files, and workflows differ.

When to Use

• Adding, removing, or switching target computer definitions, and selecting the default (slrealtime.Targets, setDefaultTargetName)
• Setting target IP, ports, or credentials (TargetSettings, setipaddr), or target-side runtime options (TargetOptions, setupTLSCertificate)
• Connecting and verifying a target, and reading its lifecycle state (connect, isConnected, status, slrealtime.testSetup)
• Target lifecycle ops: autostart on boot (setStartupApp), RTOS image update (update), reboot (reboot)

When NOT to Use

If the task crosses one of these lines, STOP and load the named skill first before writing any code, then come back.

• Model configuration — system target file, fixed-step solver, Simulink Real-Time options → simulink-configure-real-time-model.
• Application build, run, and tuning — slbuild, load(tg, app), start, stop, tg.Stimulation, setStopTime, getparam, setparam, getsignal, runtime parameters, recording, file logs, live streaming → simulink-run-real-time-application.
• Signal capture — slrealtime.Instrument, addForFileLog, addForSDI, addForMATLAB → simulink-instrument-real-time-application.
• Model-level tests — Gherkin .feature files, model_test → testing-simulink-models. slrealtime.testSetup here is a connectivity check, not a model test.
• I/O networks on the target (CAN, EtherCAT) — application-level.

Prerequisites

• MATLAB R2026a or newer, with Simulink Real-Time installed (ver lists "Simulink Real-Time")
• The support package for the hardware: Speedgoat → Speedgoat Add-On; Linux x86-64 → Embedded Coder Support Package for Real-Time Linux (requires Embedded Coder). Missing Speedgoat tooling mimics a network fault; probe with which("speedgoat.version"), not exist (references/network-setup.md).
• Target powered on and reachable for any operation requiring connect(tg) — see references/persistent-side-effects.md for the connect-required catalogue

Workflow

Step	Purpose	Asks first?
1. Inventory and status	List targets, default, connection and lifecycle state	No (read-only)
2. Read target-side options	Show live TargetOptions before any change	No (read-only)
3. Add a target	Register a new target from user-supplied name and IP	Yes
4. Set the default	Change which target slrealtime binds to	Yes
5. Update settings	Change credentials, ports, or host-side address	Yes
6. Target-side options	HTTPS/TLS and ports	Yes
7. Connect and verify	connect, status, slrealtime.testSetup	No
8. Target-side operations	setipaddr, TLS, startup app, update, reboot	Yes
9. Remove a target	Delete a target record	Yes

Use only the documented forms in references/api-reference.md (every call this skill makes, plus status(tg) return values) and the examples below. Dot-form and function-form are equivalent (connect(tg) = tg.connect()). Copy-ready starting points: references/quick-start-patterns.md.

There is no in-place mutation API for TargetSettings. To change name/address/credentials/ports, the only path is disconnect → removeTarget → addTarget (Step 5). Do not invent setTargetSettings, updateTarget, tg.TargetSettings.address = ..., etc. — those will not persist.

A target name is NOT its address. An existing name (e.g. TargetPC1) may point at a completely different IP than the one the user gave you. Before connecting to a target the user identified by IP, you MUST read slrealtime("<name>").TargetSettings.address and confirm it equals the user's IP. On a mismatch, STOP and ask — never connect on the assumption they are the same; a mismatched connect just burns a ~120 s ping timeout. See Step 3.

1. Inventory and Status (read-only)

Read which targets exist, the default, and target state, changing nothing. Covers "which targets are available", "is my target connected", "what's the status of the target". Do not invent tg.getTargets, tg.connectionStatus, or similar.

my_tgs      = slrealtime.Targets();
defaultName = getDefaultTargetName(my_tgs);
allNames    = getTargetNames(my_tgs);          % every registered target, by name

ts          = slrealtime("lab-rig-3").TargetSettings;   % one target: name, address, ports, username
allSettings = getTargetSettings(my_tgs);       % array of TargetSettings, one per target

tg = slrealtime("lab-rig-3");
connect(tg);
disp(isConnected(tg));          % true/false — NOT tg.isconnected, NOT tg.connectionState
[state, appName] = status(tg);  % 'stopped' | 'loaded' | 'running' | ... (references/api-reference.md)

isConnected(tg) answers "is it connected"; status(tg) answers "what's the status". Use both, and do not invent tg.status as a property — it is the function status(tg) (dot-form tg.status() also works). Only status(tg) needs a connection, and it auto-connects.

If the user did not specify a target, operations proceed against the default. Surface the default name and IP before any destructive op so the user can correct an unintended binding.

2. Read Live Target-Side Options Before Changing Them

On a connected target, opts = tg.TargetOptions; returns the live options (REST port, HTTPS toggle, TLS material, netrc flag). If the user asks you to "fix" something, read and present the current values first — they may have intended a different change.

3. Add a New Target

REQUIRED USER INPUT — never a best-guess operation. Before constructing TargetSettings you MUST have the user supply:

1. name — never invent a name like "lab-rig-3", "newTarget", "target1", or any placeholder. If the user did not give one, stop and ask.
2. address — the target computer's IP. Never guess; a wrong IP can collide with another machine. If the user did not give one, stop and ask.
3. username, userPassword, rootPassword — Speedgoat factory defaults are slrt / slrt / root; otherwise prompt.

Show the full proposed TargetSettings and wait for confirmation before calling addTarget. Confirmed factory defaults may be shown plainly; mask user-specific secrets.

Construct TargetSettings in a single call, passing every field as a name-value argument — the only supported form. name and address must be constructor arguments, never assignments on a pre-built object.

ts = slrealtime.TargetSettings( ...
    "name",         userProvidedName, ...
    "address",      userProvidedAddress, ...
    "sshPort",      22, ...
    "xcpPort",      5555, ...
    "username",     userProvidedUser, ...
    "userPassword", userPwd, ...
    "rootPassword", rootPwd);

addTarget(my_tgs, ts);

Refuse two anti-patterns, because neither persists: default-constructing slrealtime.TargetSettings and then assigning ts.name / ts.address (or mutating a copy of an existing settings object); and describing the settings in prose without calling the constructor. After confirmation, actually execute the constructor and addTarget — the proposed-settings summary is the confirmation step, not a substitute for running the code. Field reference: references/target-settings-schema.md.

If the intended name is already registered (or addTarget fails on a duplicate), do not assume the existing target is what the user wants and do not connect blindly:

existing = slrealtime("TargetPC1").TargetSettings;
disp(existing.address);   % compare to the address the user gave you

• Addresses match → already configured; skip addTarget and proceed.
• Addresses differ → surface both and ask: update this target's address (Step 5, or setipaddr in Step 8) or use a different name.

4. Set or Change the Default Target (Ask First — explicit confirmation required)

The default target is sticky and silent. It persists across MATLAB sessions, and every future tg = slrealtime (no name argument), in every user script, binds to it.

You MUST NOT call setDefaultTargetName unless the user explicitly asked to change the default. Adding a target does not imply "make it the default." After addTarget, ask: "Do you want me to set <name> as the default target? Your current default is <currentDefault>."

% Only after explicit confirmation that this target should become the new default:
setDefaultTargetName(my_tgs, userConfirmedName);

5. Update Credentials, Ports, or Address

There is no in-place mutation API: disconnect, remove, and re-add.

disconnect(tg);
removeTarget(my_tgs, "lab-rig-3");
addTarget(my_tgs, newTs);

The existing tg is now stale — never read the change back through it. A Target captures its TargetSettings at construction time. Clear it and verify through a fresh construction — no connection needed:

clear tg
ts = slrealtime("lab-rig-3").TargetSettings;
fprintf("%s @ %s  user %s\n", ts.name, ts.address, ts.username);

connect again only as a separate, deliberate step — never as part of the verification.

If only the target IP is changing and the target is reachable, prefer setipaddr (Step 8) — it reconfigures the NIC and updates the host-side record. Use remove+add when the IP changed outside MATLAB and you only need to refresh the host record.

6. Configure Target-Side Options

Write target-side options through dedicated APIs, not by editing the env file: HTTPS / TLS goes through setupTLSCertificate (Step 8). The XCP and REST API ports have no programmatic API in R2026a — use Simulink Real-Time Explorer → Target Properties. Schema: references/target-settings-schema.md.

7. Connect and Verify

tg = slrealtime;
connect(tg);
assert(isConnected(tg), "Failed to connect to %s", tg.TargetSettings.name);
[state, appName] = status(tg);

Call status(tg) before any op that needs to know whether an app is loaded or running. 'targetError' indicates a target-side fault; see references/network-setup.md and consider slrealtime.getCrashStack.

slrealtime.testSetup(tg); is the confidence test — ping, SSH, FTP, MQTT, REST, and a basic build/load/run cycle. On failure see references/network-setup.md; the usual cause is Windows firewall classification (Public vs. Private).

8. Target-Side Operations (Ask First)

setipaddr, setupTLSCertificate, setStartupApp, update, and reboot mutate state on the target computer itself. For each: state the side effect, show the exact call (not a prose description), and hold for confirmation. The side effect of each op is in the Ask first list under Guardrails; the summary table and full procedures are in references/target-side-operations.md.

9. Remove a Target (Ask First — explicit confirmation required)

You MUST NOT remove a target unless the user has named the exact target to remove. Do not "clean up", do not "remove the old one", do not pick from the list yourself. Removing a target deletes its credentials and IP record from MATLAB Settings — there is no undo. If the named target is the current default, removing it auto-promotes some other target to default, chosen by slrealtime.Targets rather than by the user.

Before calling removeTarget:

1. Confirm the user named a specific target (echo the name back).
2. Read getDefaultTargetName(my_tgs) and surface whether the named target is the default.
3. If it is, say so before removing, along with what the next default will be (or that you cannot tell without removing), and ask the user to confirm or set a different default first.

disconnect(tg);
removeTarget(my_tgs, userConfirmedName);

The target must be disconnected, and the only target cannot be removed. If the removed target was default, surface the newly auto-promoted default.

Verification

After any change, read state back and confirm it landed — see the "Verify after any change" pattern in references/quick-start-patterns.md.

Guardrails

Always:

• Read current settings (getTargetSettings, tg.TargetOptions) before changing them.
• When the user identifies a target by IP, read that name's on-record .TargetSettings.address and confirm it matches before connect; on a mismatch, stop and ask (see "A target name is NOT its address").
• Verify the default (getDefaultTargetName) before target-binding ops with no explicit name.
• Confirm isConnected(tg) before any method that needs a live connection (references/persistent-side-effects.md).
• Never connect while an Ask-First op awaits confirmation — it acts before consent, and an unreachable target burns a multi-minute timeout before you can even ask.
• If the user says connecting already failed, diagnose from the host record — slrealtime("<name>").TargetSettings is host-side; do not re-run the failing connect.
• Surface the side effect in plain language for any op in references/persistent-side-effects.md before calling it.
• Capture the returned tg from setipaddr — the prior one is stale. It also updates the persistent host-side TargetSettings.address, so no removeTarget/addTarget follow-up is needed.
• clear tg after a removeTarget + addTarget settings change, and never read the change back through the pre-change object — it is a construction-time snapshot. Verify via a fresh slrealtime(name).TargetSettings (Step 5).

Ask first:

• addTarget — the user MUST supply name and address. Never invent placeholder names ("lab-rig-3", "target1", "newTarget") and never guess IPs. Show the full proposed TargetSettings, passwords masked, and wait for explicit confirmation.
• setDefaultTargetName — only when the user explicitly asked to change the default. addTarget does not imply "make it the default." If the user is silent, leave the default alone and ask whether they want to switch.
• removeTarget — only when the user named the exact target. Do not "clean up" or pick a target yourself. If the named target is the current default, surface that and confirm again.
• setipaddr — reconfigures the NIC and reboots the target; session disconnects; capture the returned tg. The persistent host record updates automatically.
• setupTLSCertificate(tg, true, ...) — installs SSL material on the target computer; target must be idle (no application loaded).
• setStartupApp — the app autostarts on every boot, including unattended reboots. It must already be installed — otherwise route to simulink-run-real-time-application first.
• update(tg) — erases all applications and data from the target computer; long-running; target reboots; can brick on interruption. Tell the user about the erasure before asking for confirmation.
• reboot(tg) — disconnects all sessions; running app stops. Show the exact call, then hold for confirmation.

Never:

• Invent function names, property names, or argument forms absent from references/api-reference.md, examples, or reference files. Refuse: setTargetSettings, tg.updateTarget, tg.setIP, tg.TargetSettings.address = newAddr (none persist — use removeTarget + addTarget, or setipaddr); tg.reconnect() (use disconnect + connect); tg.Status as a property (it's the function status(tg)); start(tg, ...) / stop(tg) (those belong to simulink-run-real-time-application).
• Invent a target name or address for addTarget — both come from the user; if absent, stop and ask.
• Call removeTarget on the existing default without explicit confirmation — being asked to add a target is not permission to delete the default.
• Call setDefaultTargetName as a side effect of addTarget.
• Hard-code credentials in scripts the user keeps — prompt, or read a .env-style file they control.
• Call update(tg) or reboot(tg) on a target the user has not explicitly named — it might be a coworker's shared rig.
• Call setipaddr to "fix" a connection problem before checking the firewall and Public-vs-Private network classification (references/network-setup.md).
• Use target-shell workarounds to bypass a first-class Simulink Real-Time API — target IP, TLS, startup-app, update, and reboot all have supported APIs.
• Bypass slrealtime.Targets to write setting.matlab.slrealtime.* directly — addTarget validates duplicates and IP collisions; raw setting writes do not.

Task Routing

Task	Reference
Every API form this skill uses; status(tg) return values	references/api-reference.md
Copy-ready patterns for common tasks	references/quick-start-patterns.md
setipaddr, TLS, startup app, update, reboot — summary table and procedures	references/target-side-operations.md
TargetSettings / TargetOptions field reference	references/target-settings-schema.md
slrealtime.testSetup failures, firewall, static IP	references/network-setup.md
Which methods mutate persistent state, connect-required boundary	references/persistent-side-effects.md
Model system target file, fixed-step solver, Simulink Real-Time options	simulink-configure-real-time-model
Build, load, start, stop, tune, read signals, record, stream	simulink-run-real-time-application
Instrument-specific signal capture workflows	simulink-instrument-real-time-application

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