07 EVS Time Sync

📋 Introduction

EVS Time Sync is a high-precision time synchronization solution based on UDP protocol, designed for multi-device event camera systems. Through heartbeat mechanism and offset calculation, it ensures that the timestamps of all devices remain consistent, achieving microsecond-level time synchronization accuracy.

📋 Technical Specifications

System Requirements

  • Operating System: Ubuntu 22.04 / CentOS / RHEL
  • Build Tools: gcc, g++, build-essential
  • Network Protocol: UDP
  • Default Port: 9999 (Configurable)

Protocol Specification

  • Protocol File: time_sync_protocol.h
  • Protocol Version: 1
  • Magic Number: 0x54535943 ("TSYNC")
  • Synchronization Accuracy: Microsecond level

🔧 Dependency Description

  • Essential Dependencies: gcc, g++, pthread, librt (Usually included in system)
  • Network Library: Standard socket library

🚀 Quick Start

Compile Server Side (PC Side)

# Compile time synchronization server
make timesync

# Compilation result: generate time_sync_server executable file

Run Time Synchronization Server on PC

# Run time synchronization server (default port 9999)
./time_sync_server

# Or specify port
./time_sync_server 10000

Program running screenshot Alt text

Clean Build Files

# Clean time synchronization related build files
make clean_timesync

📡 Communication Protocol

Message Types

1. Heartbeat Message (Device → Server)

Message Type: TIME_SYNC_MSG_HEARTBEAT = 1

Structure:

typedef struct {
    TimeSyncMsgHeader_t header;
    uint64_t timestamp_us;    // Device current timestamp (microseconds)
    uint32_t sequence;        // Sequence number
} TimeSyncHeartbeatMsg_t;

Sending Frequency: Once per second

2. Offset Reply (Server → Device)

Message Type: TIME_SYNC_MSG_OFFSET_REPLY = 2

Structure:

typedef struct {
    TimeSyncMsgHeader_t header;
    int64_t  offset_us;           // Recommended time offset (microseconds)
    uint32_t reference_device_id; // Reference device ID
    uint32_t sync_quality;        // Synchronization quality (0-100)
    uint32_t sequence;            // Corresponding heartbeat sequence number
} TimeSyncOffsetReplyMsg_t;

Sending Timing: Reply immediately after receiving heartbeat

3. Status Query/Reply (Optional)

Message Type: