serialsrv 1.0.8

Serial Port Reader HTTP Service with ABAP integration

SerialSrv

A Python HTTP service that reads data from serial ports and provides it via REST API with ABAP integration support. by Altay Kirecci opriori (c)(p) 2025-09 https://www.opriori.com https://github/altaykirecci/serialsrv Since it is in beta stage, the source codes have not been made public yet.

Features

• Serial Port Reading: Read data from Arduino, sensors, and other serial devices
• HTTP API: RESTful API with JSON responses
• Host-based Access Control: Configurable IP and port restrictions
• Comprehensive Logging: Detailed request logging
• ABAP Integration: Ready-to-use ABAP client code
• Test Mode: Mock data for development and testing
• CORS Support: Cross-origin resource sharing enabled

Installation

pip install serialsrv
serialsrv --init

Quick Start

1. Basic Usage

# Copy ABAP files to current directory
serialsrv --abap

# Initialize/creating configuration file
serialsrv --init
# Start the server (default: localhost:7373)
serialsrv

# Start with custom host and port
serialsrv --host 0.0.0.0 --port 8080

# Run in test mode (returns mock data)
serialsrv --test

2. Configuration

Method 1: Using --init parameter (Recommended)

# Create configuration file in current directory
serialsrv --init

# This will create serialsrv.json with default settings
# You can then edit it to customize your configuration

Method 2: Manual creation

Create a serialsrv.json configuration file:

{
  "allowed_hosts": [
    {
      "ip": "127.0.0.1",
      "ports": [7373, 8080],
      "description": "Localhost access"
    },
    {
      "ip": "192.168.1.100",
      "ports": [7373],
      "description": "Local network access"
    }
  ],
  "serial": {
    "port": "/dev/ttyUSB0",
    "baudrate": 9600,
    "timeout": 1,
    "description": "Arduino connection"
  },
  "settings": {
    "log_file": "requests.log",
    "deny_unknown_hosts": true,
    "log_all_requests": true
  }
}

3. API Usage

GET Request

curl http://localhost:7373/

POST Request

curl -X POST http://localhost:7373/ \
-H "Content-Type: application/json" \
-d '{"test": "data"}'

Response Format

{
  "message": {
    "value": 25.5,
    "msg": "Temperature reading",
    "mode": "read",
    "result": "OK"
  },
  "timestamp": "2025-01-26T10:30:45.123456",
  "method": "GET",
  "path": "/",
  "client_ip": "127.0.0.1",
  "client_port": 54321
}

ABAP Integration

The package includes ready-to-use ABAP client code in the abap/ directory.

ABAP Client Features

• HTTP client integration
• JSON parsing with /ui2/cl_json
• Network connectivity testing
• Multiple connection options
• Detailed error handling
• Debug mode with system information
• Response headers analysis
• Object-oriented class-based approach
• Reusable methods for different scenarios

Available ABAP Files

1. serial_service_test.abap - Standalone report program
2. serial_service_method.abap - Reusable class with methods
3. serial_method_test.abap - Test program using the class methods

Using ABAP Client

Method 1: Using --abap parameter (Recommended)

# Copy ABAP files to current directory
serialsrv --abap

# This will copy all ABAP files to your current directory:
# - serial_service_test.abap (standalone report)
# - serial_service_method.abap (reusable class)
# - serial_method_test.abap (test program using the class)
# You can then copy them to your SAP system

Method 2: Manual extraction

1. Copy the ABAP code from serialsrv/abap/ directory
2. Create new ABAP programs/classes in SAP system
3. Paste the code and configure parameters
4. Run the program to test connectivity

ABAP Program Parameters

• Host: Server hostname (default: localhost)
• Port: Server port (default: 7373)
• Test Options: Multiple connection testing
• Debug Mode: System information and network diagnostics

ABAP Class Usage Examples

Using the Reusable Class

DATA: ls_result TYPE serial_service_method=>ty_serial_result,
      lv_value  TYPE string.

" Method 1: Get full result with all details
TRY.
    ls_result = serial_service_method=>call_serial_service(
      iv_host = '192.168.1.100'
      iv_port = '7373'
      iv_timeout = 10
    ).
    IF ls_result-success = abap_true.
      WRITE: / 'Value:', ls_result-value,
               / 'Message:', ls_result-message,
               / 'Mode:', ls_result-mode,
               / 'Result:', ls_result-result,
               / 'Timestamp:', ls_result-timestamp.
    ELSE.
      WRITE: / 'Error:', ls_result-error_text.
    ENDIF.
  CATCH serial_service_method=>connection_error.
    WRITE: / 'Connection error occurred'.
  CATCH serial_service_method=>timeout_error.
    WRITE: / 'Timeout error occurred'.
  CATCH serial_service_method=>parse_error.
    WRITE: / 'Parse error occurred'.
ENDTRY.

" Method 2: Get only the serial value
TRY.
    lv_value = serial_service_method=>get_serial_value(
      iv_host = '192.168.1.100'
      iv_port = '7373'
    ).
    WRITE: / 'Serial Value:', lv_value.
  CATCH serial_service_method=>connection_error.
    WRITE: / 'Connection error occurred'.
  CATCH serial_service_method=>timeout_error.
    WRITE: / 'Timeout error occurred'.
  CATCH serial_service_method=>parse_error.
    WRITE: / 'Parse error occurred'.
ENDTRY.

" Method 3: Test connection before calling
TRY.
    IF serial_service_method=>test_connection(
      iv_host = '192.168.1.100'
      iv_port = '7373'
    ) = abap_true.
      WRITE: / 'Connection successful - proceeding with data call'.
      " Now call the actual service
      lv_value = serial_service_method=>get_serial_value(
        iv_host = '192.168.1.100'
        iv_port = '7373'
      ).
    ELSE.
      WRITE: / 'Connection failed - check server status'.
    ENDIF.
  CATCH serial_service_method=>connection_error.
    WRITE: / 'Connection error occurred'.
  CATCH serial_service_method=>timeout_error.
    WRITE: / 'Timeout error occurred'.
ENDTRY.

Class Methods Available

Method	Description	Parameters	Returns
call_serial_service	Get full response with all details	host, port, timeout, test_mode	Complete result structure
get_serial_value	Get only the serial value	host, port, timeout	String value
test_connection	Test if server is reachable	host, port, timeout	Boolean success

Exception Handling

• connection_error: Network or HTTP errors
• timeout_error: Request timeout
• parse_error: JSON parsing errors

Test Program: serial_method_test.abap

This program demonstrates how to use the SERIAL_SERVICE_METHOD class with a user-friendly interface.

Features:

• Selection Screen: Easy parameter configuration
• Multiple Test Options: Test connection, get full result, or get only value
• Error Handling: Comprehensive exception handling with user-friendly messages
• Visual Feedback: Clear success/error indicators with emojis

Selection Screen Parameters:

• Host: Server hostname (default: localhost)
• Port: Server port (default: 7373)
• Timeout: Request timeout in seconds (default: 10)
• Test Options: Checkboxes to select which methods to test

Usage:

1. Run the program in SAP
2. Configure host, port, and timeout parameters
3. Select which methods to test (connection, full result, value only)
4. Execute to see the results

This program is perfect for:

• Testing the class functionality
• Demonstrating proper usage
• Debugging connection issues
• Learning how to implement the class in your own programs

Configuration Options

Serial Configuration

{
  "serial": {
    "port": "/dev/ttyUSB0",     // Serial port path (REQUIRED)
    "baudrate": 9600,           // Communication speed (REQUIRED)
    "bytesize": 8,              // Data bits: 5, 6, 7, 8 (REQUIRED)
    "parity": "N",              // Parity: N, E, O, M, S (optional)
    "stopbits": 1,              // Stop bits: 1, 1.5, 2 (optional)
    "timeout": 1,               // Read timeout in seconds (optional)
    "xonxoff": false,           // Software flow control (optional)
    "rtscts": false,            // Hardware flow control RTS/CTS (optional)
    "dsrdtr": false,            // Hardware flow control DSR/DTR (optional)
    "write_timeout": null,      // Write timeout in seconds (optional)
    "inter_byte_timeout": null, // Inter-character timeout (optional)
    "exclusive": null,          // Exclusive access mode (optional)
    "description": "Arduino"    // Optional description
  }
}

Required Parameters:

Parameter	Type	Description	Example Values
port	string	Serial port path/device name	/dev/ttyUSB0, /dev/ttyACM0, COM1, COM3, /dev/cu.usbserial-*
baudrate	integer	Communication speed in bits per second	9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600
bytesize	integer	Number of data bits per character	5, 6, 7, 8

Optional Parameters:

Parameter	Type	Description	Possible Values	Default
parity	string	Parity checking method	"N" (None), "E" (Even), "O" (Odd), "M" (Mark), "S" (Space)	"N"
stopbits	float	Number of stop bits	1, 1.5, 2	1
timeout	float	Read timeout in seconds	0.1, 1.0, 5.0, null (blocking)	null
xonxoff	boolean	Software flow control (XON/XOFF)	true, false	false
rtscts	boolean	Hardware flow control (RTS/CTS)	true, false	false
dsrdtr	boolean	Hardware flow control (DSR/DTR)	true, false	false
write_timeout	float	Write timeout in seconds	0.1, 1.0, 5.0, null (blocking)	null
inter_byte_timeout	float	Inter-character timeout in seconds	0.1, 0.5, 1.0, null (disabled)	null
exclusive	boolean	Exclusive access mode	true, false	false

Parameter Details:

• port: The serial port device path. Common examples:

  • Linux: /dev/ttyUSB0, /dev/ttyACM0, /dev/ttyS0
  • Windows: COM1, COM3, COM10
  • macOS: /dev/cu.usbserial-*, /dev/cu.usbmodem-*

• baudrate: Standard baud rates include:

  • Low speed: 300, 600, 1200, 2400, 4800, 9600
  • Medium speed: 19200, 38400, 57600, 115200
  • High speed: 230400, 460800, 921600, 1000000

• bytesize: Data bits per character:

  • 5: 5 data bits (rarely used)
  • 6: 6 data bits (rarely used)
  • 7: 7 data bits (common for ASCII)
  • 8: 8 data bits (most common)

• parity: Error detection method:

  • "N": No parity (most common)
  • "E": Even parity
  • "O": Odd parity
  • "M": Mark parity (always 1)
  • "S": Space parity (always 0)

• stopbits: Stop bits after data:

  • 1: One stop bit (most common)
  • 1.5: One and a half stop bits
  • 2: Two stop bits

• timeout: Read operation timeout:

  • null: Blocking mode (wait indefinitely)
  • 0: Non-blocking mode (return immediately)
  • >0: Timeout in seconds

• Flow Control Options:

  • xonxoff: Software flow control using XON/XOFF characters
  • rtscts: Hardware flow control using RTS/CTS signals
  • dsrdtr: Hardware flow control using DSR/DTR signals

• write_timeout: Write operation timeout (same format as timeout)

• inter_byte_timeout: Maximum time between characters in a read operation

• exclusive: Prevents other processes from accessing the same port

Host Access Control

{
  "allowed_hosts": [
    {
      "ip": "127.0.0.1",        // Client IP address
      "ports": [7373, 8080],    // Allowed ports
      "description": "Local"    // Optional description
    }
  ]
}

Settings

{
  "settings": {
    "log_file": "requests.log",     // Log file path
    "deny_unknown_hosts": true,     // Block unauthorized hosts
    "log_all_requests": true,       // Log all requests
    "encode": "utf-8"               // Character encoding for serial data
  }
}

Settings Parameters:

Parameter	Type	Description	Example Values	Default
log_file	string	Path to log file	"requests.log", "/var/log/serialsrv.log"	"requests.log"
deny_unknown_hosts	boolean	Block unauthorized hosts	true, false	true
log_all_requests	boolean	Log all HTTP requests	true, false	true
encode	string	Character encoding for serial data	"utf-8", "iso-8859-9", "ascii", "latin-1"	"utf-8"

Encoding Options:

• "utf-8": Unicode UTF-8 encoding (default, most common)
• "iso-8859-9": Turkish character support
• "ascii": Basic ASCII characters only
• "latin-1": ISO-8859-1 encoding
• "cp1252": Windows-1252 encoding
• "utf-16": Unicode UTF-16 encoding

Note: If the specified encoding fails to decode the data, the system will automatically fall back to UTF-8, and if that also fails, it will use Latin-1 as a last resort.

Command Line Options

serialsrv [OPTIONS]

Options:
  --host HOST     Host to bind to (default: localhost)
  --port PORT     Port to listen on (default: 7373)
  --test          Run in test mode (returns mock data)
  --abap          Copy ABAP files to current directory and exit
  --init          Initialize serialsrv.json configuration file and exit
  --help          Show help message

Use Cases

IoT Data Collection

• Read sensor data from Arduino/Raspberry Pi
• Provide real-time data via HTTP API
• Integrate with monitoring systems

Industrial Automation

• Connect to PLCs and industrial devices
• Provide data to SCADA systems
• Enable remote monitoring

SAP Integration

• Bridge between serial devices and SAP systems
• Real-time data integration
• Automated data collection

Development

Project Structure

serialsrv/
|-- __init__.py          # Main server code
|-- abap/                # ABAP client code
|   |-- serial_service_test.abap
|   |-- serial_service_method.abap
|   |-- serial_method_test.abap
|-- serialsrv.json       # Configuration template
|-- requirements.txt     # Dependencies

Dependencies

• pyserial>=3.5 - Serial port communication
• requests>=2.25.0 - HTTP client (for testing)

Troubleshooting

Common Issues

1. Port Already in Use

   # Use different port
   serialsrv --port 8080
   

2. Serial Port Access Denied

   # Add user to dialout group (Linux)
   sudo usermod -a -G dialout $USER
   

3. ABAP Connection Failed

   • Check if Python service is running
   • Verify network connectivity
   • Check firewall settings
   • Use debug mode in ABAP program

Log Analysis

Check the log file for detailed request information:

tail -f requests.log

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Support

• Email: [e-mail]
• https://www.opriori.com
• Issues: GitHub Issues
• Documentation: GitHub Wiki

Changelog

v1.0.0

• Initial release
• Serial port reading functionality
• HTTP API with JSON responses
• Host-based access control
• ABAP integration support
• Comprehensive logging
• Test mode support