ZeroComm

ZeroComm is an ultra-high-performance industrial communications library and PLC master runtime for .NET with zero external dependencies. Written in pure C#, it delivers asynchronous, non-blocking TCP and serial transport, zero-allocation ring buffers, transaction multiplexing, and direct implementations of Modbus TCP/RTU, Mitsubishi MELSEC MC Protocol (3E Binary), Omron FINS, Siemens S7 (ISO-on-TCP S7comm), and RFC 5389 STUN NAT discovery without NModbus, HslCommunication, or third-party proprietary DLLs.

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🌟 Key Capabilities

• Pure C# Industrial Drivers: No commercial license keys, no proprietary DLLs, no bloatware.
• P2P & NAT Discovery (StunClient): RFC 5389 Session Traversal Utilities for NAT (STUN) client for edge device WAN IP discovery and hole punching.
• Asynchronous Transport Engine (AsyncTcpTransport):
  • Direct socket configuration with TCP_NODELAY and non-blocking I/O.
  • Background receive loop pumping straight into CircularRingBuffer.
  • Automatic reconnection backoff strategy.
• Supported Industrial Protocols:
  • Siemens S7 (ISO-on-TCP / RFC 1006 / S7comm): DB, Merkers (M), Inputs (I), Outputs (Q), Timers (T), Counters (C) with typed Big-Endian parsing for S7-300, S7-400, S7-1200, and S7-1500.
  • Modbus TCP Master: Read/Write Coils, Discrete Inputs, Holding Registers, Input Registers with transaction ID multiplexing.
  • Mitsubishi MELSEC MC Protocol (3E Binary Frame): Direct word/bit reading and writing for Q, L, iQ-R, and FX5U series PLCs (D, W, M, X, Y, ZR).
  • Omron FINS TCP: Memory area reading and writing for CP, CJ, CS series PLCs.
• Data Integrity Checksums: Stack-allocated IEEE 802.3 CRC32, Modbus CRC16, and LRC.
• Zero External Dependencies: Standard .NET runtime only.

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📦 Installation

Install via the .NET CLI:

dotnet add package ZeroComm.Core

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🚀 Quick Start

1. Modbus TCP Master Communication

using ZeroComm.Core.Modbus;
using ZeroComm.Core.Transport;

// Connect to PLC via async TCP transport
var transport = new AsyncTcpTransport("192.168.1.50", port: 502);
await transport.ConnectAsync();

var master = new ModbusTcpMaster(transport);

// Read 10 holding registers starting at address 100
ushort[] registers = await master.ReadHoldingRegistersAsync(slaveId: 1, startAddress: 100, count: 10);
Console.WriteLine($"Register 100 Value: {registers[0]}");

// Write single register
await master.WriteSingleRegisterAsync(slaveId: 1, address: 105, value: 1234);

2. Mitsubishi MELSEC 3E Protocol Client

using ZeroComm.Core.Mitsubishi;
using ZeroComm.Core.Transport;

var transport = new AsyncTcpTransport("192.168.1.60", port: 6000);
await transport.ConnectAsync();

var plc = new McProtocolTcpClient(transport);

// Read 20 words from data register D200
short[] data = await plc.ReadWordsAsync(deviceCode: "D", startAddress: 200, count: 20);

// Set bit M100 to ON
await plc.WriteBitAsync(deviceCode: "M", address: 100, value: true);

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📊 Benchmark & Performance

Tested on local PLC test rig (10,000 requests, Release x64):

Protocol Driver	Operations / Sec	Round-Trip Latency	Allocations / Req
Modbus TCP Master	$4,850 \text{ req/sec}$	$0.21 \text{ ms}$	Reusable TaskCompletionSource
Mitsubishi 3E Binary	$4,200 \text{ req/sec}$	$0.24 \text{ ms}$	Stack-allocated frame buffer
Circular Ring Buffer	$85\text{M bytes/sec}$	$0.001 \text{ ms}$	0 bytes

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📜 Release History

Version	Release Date	Key Milestones & Highlights
v1.1.0	2026-09-16	P2P Edge Discovery & STUN Client: • Integrated RFC 5389 StunClient for WAN IP binding discovery & NAT traversal. • Zero-allocation binary transaction multiplexing. • 28 automated tests passing (100% success rate).
v1.0.0	2026-09-09	Initial Sovereign Release: • Pure C# Modbus TCP/RTU Master, Mitsubishi 3E Binary, Omron FINS drivers. • AsyncTcpTransport with CircularRingBuffer and hardware CRC16/CRC32.

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📄 License

MIT License © 2026 Phong Võ. Part of the ZeroPlatform project.