TurboModbus vs NModbus

TurboModbus is not a drop-in replacement for NModbus. It focuses on a narrower set of Modbus operations but adds a reactive, stream-based architecture that NModbus does not offer.

Feature Comparison

Function Codes

Function Code	TurboModbus	NModbus
FC01 Read Coils	-	yes
FC02 Read Discrete Inputs	-	yes
FC03 Read Holding Registers	yes	yes
FC04 Read Input Registers	yes	yes
FC05 Write Single Coil	-	yes
FC06 Write Single Register	yes	yes
FC15 Write Multiple Coils	-	yes
FC16 Write Multiple Registers	yes	yes
FC23 Read/Write Multiple Registers	-	yes
FC08 Diagnostics	-	partial
FC43 Device Identification	-	partial

Transport

Transport	TurboModbus	NModbus
TCP	yes	yes
UDP	-	yes
RTU (serial)	-	yes
ASCII (serial)	-	yes

Roles

Role	TurboModbus	NModbus
Client / Master	yes	yes
Server / Slave	-	yes

Data Types

Feature	TurboModbus	NModbus
Raw ushort registers	yes	yes
Float / Double / UInt32 helpers	-	yes

Architecture

Feature	TurboModbus	NModbus
Reactive streaming (Akka.Streams)	yes	-
Backpressure-aware pipeline	yes	-
Built-in polling with change detection	yes	-
Actor-based concurrency	yes	-
Custom function code extensibility	-	yes

When to Use Which

Choose TurboModbus when you need a high-throughput TCP client with reactive streaming, automatic polling, and change detection -- for example, continuously reading sensor data from industrial devices with backpressure handling.

Choose NModbus when you need broad protocol coverage (coils, serial transports, server role) or are working with devices that require function codes beyond register read/write.