SCADALite

SCADALite is a lightweight, Python-based SCADA-style dashboard that reads telemetry from either:

• Simulation mode (fake data)
• A COM/Serial device (Arduino, microcontrollers, PLCs, etc.)

It supports:

• Live trending
• Pause/Resume
• Alarm detection (HI/LO)
• Configurable alarms
• Historical log loading
• Config-driven graph selection

Design choices

• Tkinter is single threaded, so one thread is allocated for GUI and other for background reading to prevent freezes.
• Safe shutdown of thread using stop event
• Unified record parser, everything is parsed by one function and into one structure (TagRecord)
• Streams do not store or process data to prevent race conditions

File Structure

scadalite/
│
├── app.py          ← GUI
├── streams.py      ← simulation + COM
├── parser.py       ← TagRecord + parse_line
├── alarms.py       ← alarm_rules + active_alarms + detect_alarm
├── storage.py      ← history + latest + log_record + handle_record
├── config.py
└── main.py

Installation

git clone https://github.com/colinli02/scadalite
cd scadalite
pip install -r requirements.txt

Configuration and Usage

Modify config.yaml with the tags you want to use. See the current config for examples.

Tag Types

SCADALite parses every incoming telemetry line into a TagRecord with the following fields:

• TAG — name of the measurement
• TYPE — the kind of signal
• PV — process value (numeric reading)
• SP — setpoint (optional)
• UNIT — engineering units (optional)
• TS — timestamp

Available Signal Types

Type	Meaning
ai	Analog input (sensor value, e.g., speed, temperature, level)
do	Digital output (0/1 command, e.g., heater on/off)
CONST	Constant value defined in config.yaml

COM Input Formats

SCADALite supports multiple input formats depending on how much information you want to send.

Simple Format

TYPE defaults to ai.

Simple Format Syntax

TAG PV

Simple Format Example

PUMP1_SPEED 1500

Parsed Values

• TYPE = ai
• PV = 1500
• SP = (empty)
• UNIT = (empty)

Key/Value Format

Explicitly specify TYPE, SP, and UNIT.

Key/Value Example

TAG=PUMP1_SPEED;TYPE=ai;PV=1332.8;SP=1500;UNIT=RPM;

Supported Fields

• TYPE
• PV
• SP
• UNIT

CSV Format

CSV Syntax

TAG,TYPE,PV,SP,UNIT

CSV Example

PUMP1_SPEED,ai,1332.8,1500,RPM

Constants

You can define constant tags directly in config.yaml.

Constant Configuration Example

constants:
  TARGET_SPEED: 1500
  TARGET_LEVEL: 80

These appear with:

• TYPE = CONST
• PV = your constant value
• SP = (empty)

Constants are graphed by default.

Running SCADALite

Run from the project root (cd)

py -m scadalite.main

Or run the .bat file directly on Windows