Collaborative Application of Serial to Ethernet Converter and Industrial Switch in Industrial Control Scenarios: Network-Based Innovation in Centralized Control Boxes

Core Pain Points of Industrial Control Networking

In industrial sites dominated by non-standard automated control cabinets, equipment networking has long faced the dual dilemmas of "protocol silos" and "transmission bottlenecks." Traditional serial devices (e.g., PLCs, sensors, instruments) are constrained by the physical limitations of RS-232/485, resulting in short communication distances and poor scalability. While industrial Ethernet offers high-speed transmission advantages, it struggles to directly integrate legacy equipment. This conflict is particularly pronounced in centralized control box scenarios, where limited space necessitates the integration of multiple device types while meeting intelligent demands such as real-time monitoring and remote operation and maintenance.

The collaborative application of serial to Ethernet converters and industrial switches represents a critical technological pathway to resolve this challenge. By converting serial protocols to TCP/IP, serial to Ethernet converters enable traditional devices with network communication capabilities, while industrial switches establish a stable and reliable local area network (LAN) backbone for high-speed data exchange between devices. This article provides an in-depth analysis of the application logic, implementation considerations, and typical case studies of this technological combination in industrial control scenarios.

1. Technological Synergy: From Protocol Conversion to Network Architecture

1.1 Core Functionality Analysis of Serial to Ethernet Converters

Serial to Ethernet converters are essentially "protocol converters + network interfaces." Taking the USR-N520 as an example, its technical characteristics perfectly align with industrial scenario requirements:

• Multi-protocol Support: Built-in optimized TCP/IP protocol stack supports Modbus RTU/TCP bidirectional transparent transmission, enabling seamless integration with PLCs, sensors, and other devices. For instance, in an automotive component production line, 20 RS-485-interface weighing instruments were connected to a LAN via the N520, enabling real-time production data collection.
• Flexible Operating Modes: Offers multiple modes, including TCP Server/Client, UDP, HTTPD Client, and WebSocket. In an intelligent building scenario, the WebSocket mode allowed an air conditioning control system to directly obtain temperature and humidity sensor data via a webpage, simplifying system architecture.
• Hardware-Level Protection: Features 6000V lightning protection, ESD protection, and a wide temperature design (-40°C to 85°C), ensuring stable operation in electromagnetic interference-prone industrial environments. Field testing in a steel plant blast furnace monitoring project demonstrated that the N520 operated fault-free for 18 months in a 120°C furnace front environment.

1.2 Architectural Support Role of Industrial Switches

The USR-ISG series industrial switches build reliable LANs through the following characteristics:

• Ring Redundancy Technology: Achieves 50ms-level fault self-healing based on the ERPS protocol. In a rail transit project, the ISG switch-based ring network reduced business switching time by 90% compared to traditional STP protocols after a fiber optic cable break.
• Hybrid Port Configuration: Provides combinations of 5/8/16 electrical ports + 2 optical ports, supporting 10/100/1000Mbps adaptive speeds. For example, in a wastewater treatment plant, 2 optical ports connected remote pumping stations, while electrical ports integrated local control cabinets, reducing wiring costs by 60%.
• Industrial-Grade Reliability: Features IP40 protection, fanless cooling, and an MTBF of 300,000 hours. Field testing in a photovoltaic power plant showed that the ISG switch reduced power module failure rates by 82% compared to commercial switches in -30°C freezing conditions.

2. Implementation Considerations for Centralized Control Box Scenarios

2.1 Space Optimization Design

Given the compact internal space of non-standard control cabinets, key considerations include:

• Device Selection: Prioritize DIN rail-mounted products. The USR-ISG series, with its aluminum alloy housing, improves thermal conductivity by 3x compared to plastic housings, ensuring stable operation in 40°C cabinet environments.
• Wiring Specifications: Use shielded twisted-pair cables to connect serial to Ethernet converters and devices, keeping cable lengths under 100 meters. Field testing in an electronics factory revealed that excessive cable lengths increased packet loss rates to 15%.
• Electromagnetic Compatibility: Maintain a minimum device spacing of 15cm and avoid parallel routing of power and signal cables. In an injection molding machine retrofit project, optimized wiring reduced communication error rates caused by electromagnetic interference from 3.2% to 0.07%.

2.2 Critical Network Configuration Parameters

• IP Address Planning: Adopt a hybrid static IP and DHCP model. Core devices (e.g., PLCs) are assigned static IPs, while terminal devices like sensors use DHCP for automatic address acquisition. This approach reduced IP conflicts by 98% in a chemical project.
• VLAN Segmentation: Divide virtual LANs by device type. For example, isolate video surveillance data streams from control commands to prevent bandwidth contention. Field testing showed that VLAN deployment reduced critical control command latency to under 5ms.
• QoS Policies: Prioritize real-time protocols like Modbus TCP. In a packaging machinery project, QoS optimization shortened device response times by 40%.

3. Typical Application Scenario Analysis

3.1 Smart Manufacturing Production Line

Automotive Engine Assembly Line Retrofit Project:

• Equipment Networking: Eight USR-N520 converters connected 32 RS-485-interface torque wrenches to a LAN, enabling real-time torque data upload.
• Network Architecture: A USR-ISG-16T switch formed a ring network with ERPS protocol support, ensuring uninterrupted operations during node failures.
• Implementation Results: Equipment utilization increased by 25%, and first-pass product yield rose from 92% to 98.7%.

3.2 Energy Management System

Photovoltaic Power Plant Monitoring Project:

• Data Collection: USR-N520 converters transformed RS-232 data from 200 inverters into Modbus TCP, which was then transmitted to the control center via fiber optics.
• Network Redundancy: Dual-switch hot standby and dual-link redundancy designs achieved 99.999% availability.
• Economic Benefits: Fault response times shortened from 2 hours to 15 minutes, boosting annual power generation by 1.8%.

3.3 Intelligent Building Control

Commercial Complex Building Automation Project:

• Device Integration: Serial to Ethernet converters connected over 2,000 devices (e.g., HVAC, lighting, elevators) to a BACnet/IP network.
• Bandwidth Optimization: USR-ISG switches supported port speed limiting to prevent video surveillance traffic from consuming control network bandwidth.
• Management Efficiency: Maintenance personnel resolved 90% of faults via a web interface, reducing labor costs by 35%.

4. Technological Evolution Trends

4.1 Deepened Protocol Convergence

With the maturation of Time-Sensitive Networking (TSN) technology, industrial switches will achieve deeper IT/OT protocol convergence. The next-generation USR-ISG products already feature reserved TSN interfaces, supporting novel protocols like OPC UA over TSN to enable unified network transmission of motion control and data analytics.

4.2 Edge Computing Empowerment

Serial to Ethernet converters are evolving from mere protocol converters into edge computing nodes. Upcoming USR-N520 versions will integrate Python runtime environments, enabling on-device data preprocessing and anomaly detection. A predictive maintenance pilot project demonstrated that edge computing reduced data transmission volumes by 70% while lowering cloud computing loads.

4.3 Enhanced Security Protections

To counter industrial internet security threats, next-generation devices will incorporate encrypted communication modules. The USR-ISG series, already certified under IEC 62443, supports security mechanisms like MAC address binding and 802.1X authentication to defend against common threats such as ARP spoofing and DDoS attacks.

Building the Foundation for Industrial Networking

The collaborative application of serial to Ethernet converters and industrial switches essentially constructs a "digital bridge" connecting traditional and future-oriented industrial systems. In non-standard automated control cabinet-dominated industrial sites, this technological combination revitalizes legacy equipment through triple safeguards—protocol conversion, network architecture, and security protection—providing foundational support for strategies like smart manufacturing and the Industrial Internet. As TSN, edge computing, and other technologies continue to integrate, this collaborative model will evolve toward higher reliability, lower latency, and greater intelligence. For system integrators and end-users, selecting mature products validated in harsh environments will be a critical step toward achieving industrial networking transformation.