Lab Control Interface

A browser-based instrument control panel for the lab_api project. Control and monitor your Multicomp Pro bench equipment from any browser on the same network — no driver installation needed on the client side.

## this repo contains the UI, API and device drivers. ---

Supported instruments

Device	Model	Protocol	Default address
Power Supply	MP711001	TCP	192.168.1.100:5025
Multimeter	MP730027	TCP	192.168.1.99:3000
DC Load	MP71077x	UDP	192.168.1.80:18190

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Files

lab_api/
├── lab_api/                  ← original lab_api driver package
│   ├── psu_device/
│   ├── multimeter_device/
│   └── dcload_device/
├── server.py                 ← Flask server (this project)
├── lab_control.html          ← Web UI (this project)
└── README.md

Place server.py and lab_control.html in the root of the lab_api repository (next to the lab_api/ package folder).

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Quick start

1. Install dependencies

pip install flask flask-cors

2. Start the server

python server.py

The server starts on port 5000 and connects to instruments at their default IPs. Open http://localhost:5000 in any browser.

3. Connect instruments

Enter the server URL in the header bar (http://localhost:5000 if running locally) and click CONNECT ALL. Each device card shows a green indicator when reachable.

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Running without hardware — Stub mode

If the lab_api drivers cannot be imported the server starts in stub mode automatically. All API calls return realistic simulated data (including ±0.5 % noise and sinusoidal waveforms). This lets you develop, test, or demo the UI without any instruments connected.

WARNING  lab_server: lab_api drivers not found. Running in STUB mode

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Command-line options

python server.py [options]

--psu-ip   IP     PSU IP address          (default: 192.168.1.100)
--psu-port PORT   PSU TCP port            (default: 5025)
--mm-ip    IP     Multimeter IP address   (default: 192.168.1.99)
--mm-port  PORT   Multimeter TCP port     (default: 3000)
--dcl-ip   IP     DC Load IP address      (default: 192.168.1.80)
--dcl-port PORT   DC Load UDP port        (default: 18190)
--port     PORT   Flask server port       (default: 5000)
--debug           Enable Flask debug mode

Example — instruments on non-default addresses:

python server.py --psu-ip 10.0.0.10 --mm-ip 10.0.0.11 --dcl-ip 10.0.0.12 --port 8080

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UI walkthrough

Header bar

Control	Purpose
SERVER field	Base URL of the Flask server (change if accessing remotely)
CONNECT ALL	Pings all three devices at once; coloured indicators show status
Poll rate	Interval for automatic measurement polling (1 / 2 / 5 / 10 s)
START POLLING	Begins automatic polling of all devices at the selected rate

Power Supply card

• CH1–CH4 tabs — select which channel all controls apply to
• Voltage / Current sliders — drag or type directly in the number field; slider fills with colour as it moves
• APPLY — sends the current voltage and current-limit setpoints to the selected channel
• OUTPUT ON/OFF — toggles the channel output; button turns green when on
• MEASURE — reads back actual voltage and current from the instrument and plots the values

Multimeter card

• Mode buttons — select measurement type: DC V, AC V, DC A, AC A, Ω, continuity, diode, capacitance, frequency
• MEASURE — takes a single reading; updates the large display and min/max trackers
• RESET MIN/MAX — clears the running min/max without affecting the chart

DC Load card

• Mode buttons — CC (constant current), CV (constant voltage), CP (constant power), CR (constant resistance); switching mode updates the slider range and unit automatically
• Set value slider — sets the target for the active mode
• APPLY — sends mode and setpoint to the instrument
• LOAD ON/OFF — engages or disengages the load; button turns green when on
• MEASURE — reads back voltage, current, and calculates dissipated power

Live Data chart

• Plots PSU voltage, PSU current, DMM reading, load voltage, and load current on a shared time axis (up to 120 samples)
• Click any legend button to show/hide individual series
• CLEAR — wipes chart history
• EXPORT CSV — downloads all plotted data as a .csv file

Config Manager

Saves and restores complete instrument setups (server URL, all setpoints, modes, and channel selection) to browser localStorage.

Button	Action
SAVE CONFIG	Saves current state under the typed name (auto-named if blank)
LOAD	Restores that config — sliders, modes, and server URL all update
✕	Deletes that config
EXPORT JSON	Downloads all saved configs as a single .json file
IMPORT JSON	Merges configs from a previously exported .json file

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Accessing from another machine

The server binds to 0.0.0.0 so it is reachable from anywhere on the local network. On the remote machine open:

http://<server-host-ip>:5000

And set the SERVER field in the UI to the same URL. CORS is enabled, so the browser will not block cross-origin API calls.

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Troubleshooting

Instrument shows red indicator after CONNECT ALL

• Verify the instrument is powered on and connected to the same network.
• Confirm the IP address with ping <ip> from the server machine.
• Check that no firewall is blocking the instrument's port (5025 / 3000 / 18190).
• Try the individual PING button on that device's card for a targeted test.

Server starts in stub mode unexpectedly

• Make sure server.py is in the root of the lab_api repo (same level as the lab_api/ package folder).
• Check that all lab_api dependencies are installed: pip install -r lab_api/requirements.txt

Browser shows "Failed to fetch"

• The browser is being served from a different origin than the API. Make sure the SERVER field matches the actual server address (not localhost if you opened the HTML as a file).

PSU APPLY has no effect

• Make sure OUTPUT is ON for that channel — some instruments ignore setpoint changes while the output is disabled.