Package promo on DUB

To use this package, run the following command in your project's root directory:

A minimal D library to build Modbus over TCP payloads.

This package implements the binary formatting of MODBUS requests and responses when transported over a MODBUS TCP/IP network. It focuses solely on the creation of the data blob (including the MBAP header and PDU), without handling the transport layer (i.e., TCP socket communication).

For networking, the user is expected to rely on Phobos or any other library of choice.

Features

Encodes MODBUS TCP request/response payloads
Supports MBAP header creation
Stateless and lightweight
Fully compatible with standard MODBUS TCP/IP devices
Pure D implementation

Installation

Add this package as a dependency in your dub.sdl or dub.json project file.

`dub.sdl`

dependency "promo" version="~>0.1.0"

`dub.json`

"dependencies": {
    "promo": "~>0.1.0"
}

MBAP Header Structure

Each MODBUS TCP frame starts with a 7-byte MBAP (MODBUS Application Protocol) header:

Field	Size	Description
Transaction ID	2 bytes	Identifier for pairing requests and responses
Protocol ID	2 bytes	Always `0` for MODBUS
Length	2 bytes	Number of remaining bytes (Unit ID + PDU)
Unit ID	1 byte	Identifies the MODBUS slave device

This header is followed by the Protocol Data Unit (PDU), which includes the function code and associated data.

Usage Example

See cli.

Notes

This library does not implement TCP communication.
You are expected to use std.socket or a similar transport layer to send and receive the data.
Error handling and response parsing are also outside the scope of this package (for now).

Contributing

Pull requests and issues are welcome. If you find a bug or want to add support for additional MODBUS function codes, feel free to contribute!

License

MIT

promo ~master

promo