Dalam automasi industri dan aplikasi IoT, pelayan bersiri dan pintu masuk modbus kedua-duanya penting untuk menyambungkan peranti bersiri lama ke rangkaian moden. Mereka mungkin mempunyai fungsi yang bertindih, tetapi ia tidak selalu boleh ditukar ganti.
Panduan ini menerangkan:
✔ What Serial Servers and Modbus Gateways do
✔ Key differences between them
✔ When to use each device
✔ Real-world applications
Apakah Pelayan Bersiri?
A Serial Server (also called a Serial-to-Ethernet Converter) is a device that enables bidirectional transparent data transmission between RS-232/485/422 serial ports and TCP/IP networks. There are various types of serial servers, such as single serial port RS-485 to network, RS-232 to network, dual serial port RS-485/RS-232 to network, and RS-232 and RS-485 serial ports work independently at the same time without affecting each other. There are also 4-port, 8-port, 16-port, etc.
Ciri-ciri Utama Pelayan Bersiri
✅ Ketelusan Protokol – Transmits raw serial data without modification
✅ Menyokong Piawaian Berbilang Siri – RS-232, RS-485, RS-422
✅ Sokongan Port COM Maya – Allows legacy software to work over Ethernet
✅ Komunikasi Jarak Jauh – Extends serial connections globally via the internet
Kegunaan Biasa Pelayan Bersiri
- Connecting CNC machines, barcode scanners, or PLCs to a network
- Remotely accessing legacy industrial equipment
- Extending serial communication beyond RS-485 distance limits
Apakah Gerbang Modbus?
A Modbus Gateway is a specialized device that converts Modbus RTU/ASCII to Modbus TCP (and vice versa). It acts as a protocol translator, enabling Modbus serial devices to communicate over Ethernet.
Ciri-ciri Utama Gerbang Modbus
✅ Penukaran Protokol – Modbus RTU ↔ Modbus TCP
✅ Sokongan Multi-Master – Multiple hosts can query devices simultaneously
✅ Pemetaan ID Hamba – Allows duplicate device IDs in the same network
✅ Penimbalan Data – Caches responses to speed up queries
Kegunaan Biasa Gerbang Modbus
- Integrating Modbus RTU PLCs into SCADA systems
- Aggregating data from multiple sensors in smart agriculture
- Enabling cloud monitoring of industrial equipment
Pelayan Bersiri lwn Gerbang Modbus: 5 Perbezaan Utama
| Ciri | Pelayan Bersiri | Gerbang Modbus |
|---|---|---|
| Fungsi Utama | Penukaran siri-ke-Ethernet yang telus | Modbus RTU ↔ Modbus TCP conversion |
| Sokongan Protokol | Semua protokol bersiri (data mentah) | Hanya Modbus RTU/ASCII & Modbus TCP |
| Sokongan Multi-Master | ❌ Only one host can communicate at a time | ✅ Multiple hosts can query devices |
| Pengendalian ID Budak | Memerlukan ID unik untuk setiap peranti | Membenarkan ID pendua (menyokong pemetaan) |
| Penimbalan Data | ❌ No caching | ✅ Stores responses for faster queries |
Bila hendak menggunakan Pelayan Bersiri vs Gerbang Modbus?
Pilih Pelayan Bersiri Jika Anda Perlu:
🔹 Komunikasi bersiri telus (tiada penukaran protokol)
🔹 Sokongan untuk peranti bukan Modbus (cth, pengimbas kod bar, pencetak)
🔹 Fungsi port COM maya
Pilih Gerbang Modbus Jika Anda Perlu:
🔹 Modbus RTU kepada Modbus TCP penukaran
🔹 Berbilang hos mengakses peranti yang sama
🔹 Pemetaan ID hamba (ID pendua dibenarkan)
🔹 Masa tindak balas yang lebih pantas dengan penimbalan data
Contoh Dunia Nyata
Kes Penggunaan Pelayan Bersiri
A factory uses a Serial Server to connect an old RS-485-based CNC machine to a modern MES system. Since the CNC uses a proprietary protocol (not Modbus), a Serial Server is the best choice.
Kes Penggunaan Modbus Gateway
A water treatment plant uses a Modbus Gateway to connect 10 Modbus RTU PLCs to a cloud-based SCADA system. The gateway converts RTU to TCP, allowing multiple operators to monitor the system simultaneously.
S1: Bolehkah Pelayan Bersiri berfungsi dengan peranti Modbus?
A: Yes, but it only forwards raw data—it does not convert protocols. You’ll need additional software to handle Modbus TCP.
S2: Bolehkah Modbus Gateway menggantikan Pelayan Bersiri?
A: Only if all devices use Modbus RTU/ASCII. If non-Modbus devices are involved, a Serial Server is needed.
S3: Manakah yang lebih baik untuk sistem SCADA?
A: A Modbus Gateway is ideal for SCADA because it supports multi-master communication and data buffering.
