# Modbus Protocol for .NET | Common

This package contains all basic tools to build your own clients.

### Contracts

**IModbusConnection**    
This is the interface used on the base client to communicate with the remote device.
If you want to use a custom connection type, you should implement this interface yourself.    
The `IModbusConnection` is responsible to open and close the data channel in the background.

**IModbusProtocol**    
If you want to speak a custom type of protocol with the clients, you can implement this interface.

**ModbusBaseClient**    
This abstract base client contains all the basic methods and handlings required to communicate via Modbus Protocol.
The packages `AMWD.Protocols.Modbus.Serial` and `AMWD.Protocols.Modbus.Tcp` have specific derived implementations to match the communication types.


### Enums

Here you have all typed enumerables defined by the Modbus Protocol.

- Error code
- Function code
- Device Identification Category (Basic, Regular, Extended, Individual)
- Device Identification Object
- ModbusObjectType (only needed when using the abstract base type `ModbusObject` instead of `Coil`, etc.)


### Extensions

To convert the Modbus specific types to usable values and vice-versa, there are some extensions.

- Decimal extensions for `float` (single) and `double`
- Signed extensions for signed integer values as `sbyte`, `short` (int16), `int` (int32) and `long` (int64)
- Unsigned extensions for unsigned integer values as `byte`, `ushort` (uint16), `uint` (uint32) and `ulong` (uint64)
- Some other extensions for `string` and `bool`


### Models

The different types handled by the Modbus Protocol.

- Coil
- Discrete Input
- Holding Register
- Input Register

In addition, you'll find the `DeviceIdentification` there.    
It is used for a "special" function called _Read Device Identification_ (0x2B / 43), not supported on all devices.

The `ModbusDevice` is used for the `VirtualModbusClient`.    
In combination with the *Proxy implementations (in the derived packages) it can be used as server.


### Protocols

Here you have the specific default implementations for the Modbus Protocol.

- ASCII
- RTU
- TCP
- [RTU over TCP]

**NOTE:**    
The implementations over serial line (RTU and ASCII) have a minimum unit ID of one (1) and maximum unit ID of 247 referring to the specification.
This validation is _not_ implemented here due to real world experience, that some manufactures don't care about it.

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Published under MIT License (see [choose a license])



[RTU over TCP]:     https://www.fernhillsoftware.com/help/drivers/modbus/modbus-protocol.html
[choose a license]: https://choosealicense.com/licenses/mit/