scanengine-3/HELIOS_TEST_README.md

Helios Laser Test Application

A simple PyQt6 GUI application for testing and controlling the Helios pulsed laser system.

Features

• Connection Management: Connect/disconnect to the laser via RS-232 serial port
• Frequency Control: Set and query laser pulse frequency (16,700 - 125,000 Hz)
• Current Control: Set and query pump diode current (0 - 7,000 mA)
• Pulse Mode: Select from three pulse modes:
  • Single Pulse
  • Continuous Gating
  • Continuous Pulsing
• Laser Enable/Disable: Control laser emission with dedicated buttons
• System Information: Query and display controller and head serial numbers
• Power Monitoring: Query and display output power in mW
• Message Log: Real-time log of operations and responses

Usage

Starting the Application

/opt/scanengine-3/run_helios_test.sh

Or directly:

source /opt/srasenv/bin/activate
cd /opt/scanengine-3
python3 helios_test_app.py

Connection

1. Select Serial Port: Choose the appropriate serial port from the dropdown (e.g., /dev/ttyUSB0)
2. Refresh Ports: Click "Refresh Ports" to update the list of available ports
3. Connect: Click "Connect" to establish connection with the laser
4. Once connected, the status will show "Connected to [port]" in green

Control Tab

Frequency Control

• Enter desired frequency (16,700 - 125,000 Hz)
• Click Set Frequency to apply the setting
• Click Query to read the current frequency from the laser

Current Control

• Enter desired pump diode current (0 - 7,000 mA)
• Click Set Current to apply the setting
• Click Query to read the current from the laser

Pulse Mode Control

• Select desired pulse mode from dropdown
• Click Set Mode to apply the setting

Laser Control

• Enable Laser: Starts laser emission
• Disable Laser: Stops laser emission
• Query Status: Checks if laser is currently enabled/disabled

Monitor Tab

System Information

• Query All: Queries all available parameters from the laser
• Controller SN: Displays controller serial number
• Head SN: Displays laser head serial number

Power Monitoring

• Query Power: Reads output power in mW

Messages

• Real-time log of all operations and responses
• Useful for debugging and verifying commands

RS-232 Communication Settings

The driver uses the following settings (automatic, no configuration needed):

• Baud Rate: 9600
• Data Bits: 8
• Parity: None
• Stop Bits: 1
• Flow Control: None
• Timeout: 1 second

Command Reference

The application uses the following Helios commands:

Command	Function	Range
FP=value	Set frequency period (ns)	8,000 - 60,000
FP?	Query frequency period	-
PC=value	Set pump current (mA)	0 - 7,000
PC?	Query pump current	-
PM=value	Set pulse mode (0-2)	0=Single, 1=Gate, 2=Continuous
LE=value	Set laser enable (0/1)	0=Off, 1=On
LE?	Query laser enable status	-
PO?	Query output power (mW)	-
SN?	Query controller serial	-
HSN?	Query head serial	-

Safety Notes

⚠️ IMPORTANT: Please follow these safety precautions when using the laser:

1. Door Switch: Ensure the laser enclosure door switch is closed during operation
2. Laser Disable Pin: The laser disable pin (pin 3) must be properly connected
3. Residual Emission: The laser may emit when the door switch is open - always treat it as potentially dangerous
4. Start Low: When setting current, start at lower values and increase gradually
5. Monitor Power: Use the "Query Power" function to verify safe output levels

Troubleshooting

Cannot Connect

• Verify the correct serial port is selected
• Check that the USB-to-RS-232 adapter is properly connected
• Ensure no other application is using the same port
• Try clicking "Refresh Ports" to update the list

Commands Not Working

• Verify the laser is connected (status shows green)
• Check that the laser is not in error state
• Review the message log for error details

Serial Numbers Not Showing

• The laser may not respond if not properly powered
• Check the serial connection
• Try the "Query All" button to get diagnostic information

Files

• helios_test_app.py - Main application
• run_helios_test.sh - Launcher script
• hardware/helios_laser.py - Helios driver
• docs/protocols/helios_comms_protocol.pdf - Official Helios documentation

Requirements

• Python 3.8+
• PyQt6
• pyserial
• Helios laser with RS-232 interface
• USB-to-RS-232 adapter (if using modern computer)