DB9 to RJ45 female serial Adapter can be used to convert DB9 serial port connection to an RJ45 mould jack. Support serials signals (RS-232 Communication)to be transmitted over Cat5e/Cat6/Cat7 networking cables. Widely used in industrial control, network equipment debugging (such as Console port management of routers, switches, and servers), and other scenarios. Enabling connection and communication between old serial devices and modern network interfaces. But pls note that Serial to Ethernet adapter cannot transfer serial communication to Ethernet networking.
How about DB9-to-RJ45 pinout diagram?
Typical DB9-to-RJ45 pinout diagram used for RS-232 serial communication-especially for console or serial device connections:
Serial to Ethernet adapter pinout connection can be customized to match device requirements. Starte makes DIY type RS232 Serial to Ethernet Console Converter, which leaves 9 tinned wires, which you can connect with RJ45 port as your demand.
How does DB9 serial port to RJ45 network cable adapter works?
Signal Mapping
Inside DB9 to RJ45 modular adapter, Pins of the DB9 connector are connected to the corresponding pins of RJ45 female connector according to a pre-defined wiring standard. For example:
DB9 Pin 2 (RXD) → RJ45 Pin 6
DB9 Pin 3 (TXD) → RJ45 Pin 3
DB9 Pin 5 (GND) → RJ45 Pin 4 or 5
This mapping complies with common serial to RJ45 wiring standards and ensures correct data transmit and receive directions.
Physical Conversion Only, No Protocol Processing
Most RS232 serial to LAN interface adapters do not support protocol conversion. They only transmit RS232 level signals through the RJ45 interface, so both connected devices must still support serial communication mode.
To achieve real"serial to Ethernet" remote communication, a Serial to Ethernet Converter is required to perform protocol encapsulation and IP transmission.
Application of DB9 RS232 to Cat5e connection serial Adapter
1.Networking & IT Equipment Configuration
9-pin serial to RJ45 jack console adapter can connect PC serial port to console port on network or IT devices for configuration or diagnostics. Suitable for routers, switches, and firewalls. Compatible with most Huawei, ASUS, Cisco, ZTE,Linksys, Netgear Router. You can connect a laptop's COM port to a Cisco router console using Cat5e networking cable and 9-pin serial to RJ45 jack console adapter.
2. Industrial Automation & Control Systems
RJ45 to DB9 serial adapter is suitable for PLC (Programmable Logic Controller) communication, and more easier to convert RS232 DB9 serial ports to RJ45 cabling and longer-distance serial communication in factory automation systems. You can Link computer or HMI (Human Machine Interface) to a PLC with Cat5 networking cable and RJ45 to DB9 serial adapter.
3. Serial Communication Extension
RJ45 Female Socket to 9pin Serial DB9 Modular Adapter can be used to extend RS232 connections over Cat5e networking cables, support Networking cable to carry serial signals over long distance. You can use RJ45 Female Socket to 9pin Serial DB9 Modular Adapter and 50-100 feet Cat5e Lan cable to connect barcode scanner, POS terminal, or serial printer located far from PC.
4. Data Acquisition & Embedded Systems
DB9 RS232 to RJ45 Modular Adapter can be used with DAQ devices or embedded boards which is communicate via RS232 but are physically separated. Compatible with sensors, microcontrollers, or data loggers. You can use DB9 RS232 to RJ45 Modular Adapter and Cat6 networking cable to connect microcontroller board's DB9 serial output to a monitoring PC.
5. Custom Serial Wiring or Adaptation
RS232 serial to RJ45 Lan converter adapter is supported to reassign Pin connection and suitable for custom or proprietary serial wiring setups. RJ45 female connector pinout is fixed, you can custom DB9 connection pinout configuration. You can use RS232 serial to RJ45 Lan converter adapter to create customized Pinout wiring for industrial device that uses a unique RS232 configuration.
6. POS (Point of Sale) & Peripheral Devices
DB9 to RJ45 Modular Serial Adapter can be used to change between DB9 ports on computers and RJ45 ports used on cash registers, printers, or scales. Compatible with most serial-based POS equipment. You can use DB9 to RJ45 Modular Serial Adapter to achieve Serial communication between a POS terminal and a receipt printer via RJ45 cabling.
7. Communication in Building or Energy Systems
Modular Serial to Ethernet Console Server Adapter can be used to
facilitate RS232 communication in building management or energy monitoring systems where long cable runs are required. Suitable with monitoring systems (HVAC, energy meters, BMS). You can use Modular Serial to Ethernet Console Server Adapter to connect an energy monitoring module with an RS232 port to a control server using RJ45 cabling.
Starte is a direct factory specializing in RS232 DB9 to RJ45 modular adapters, with rich experience in industrial serial port connection and communication accessories. Our RJ45 to DB9 serial console adapter features tinned copper conductors and thick gold-plated contacts, which ensures stable signal transmission, strong anti-interference performance and high plug-and-unplug durability. Widely applied in industrial automation, security monitoring, equipment debugging and network wiring fields.
We support OEM & ODM customization, customized pin connection and colorful hood is supported. Fast response for small orders and stable supply for bulk orders. Strict quality control is implemented throughout production, dedicated to providing reliable and cost-effective industrial connection solutions for global customers.
Main DB9 to RJ45 serial adapter is as follows:
DB9 male to RJ45 female adapter
DB9 female to RJ45 female adapter
FAQ Of DB9 to RJ45 serial Adapter:
1. What is a DB9 to RJ45 serial adapter?
DB9 to RJ45 adapter can convert 9-pin RS232 serial interface into an RJ45 (8P8C) networking interface, commonly used with standard network cables (Cat5/Cat6) for serial communication.
2. What is DB9 to RJ45 serial Adapter used for?
DB9 to RJ45 serial Adapter mainly used to connect computers, routers, receiver printer, POS, and industrial devices for serial data communication.
3. Does DB9 to RJ45 serial Adapter convert RS232 signals to Ethernet?
❌ No. DB9 to RJ45 serial Adapter is just only changed DB9 serial connector to RJ45 networking interface. It is not convert the electrical or data protocol.
4. Can I use any Ethernet cable with DB9 to RJ45 socket serial Adapter?
✅ Yes. You can use standard Ethernet cable(Such as Cat5e/Cat6/Cat7/Cat8 Lan cable) to connect between two DB9 interface to RJ45 adapters or to compatible console port.
5. Is DB9 to RJ45 modular Adapter pinout standard for all devices?
❌ No. DB9 to RJ45 serial Adapter pin configuration is varied depending on device manufacturer requirement. (e.g., Cisco, Juniper, or custom systems).
Before you buy this DB9 to RJ45 serial Adapter, pls confirm whether this serial to Ethernet adapter pinout wiring is matched with your device.
6. Can I use DB9 to RJ45 console Adapter for networking or internet connection?
❌ No. DB9 to RJ45 serial Adapter just transfer serial RS232 signals, not Ethernet data packets.
7. How far can I extend the RS232 signal using this RJ45 to DB9 serial Adapter?
When use with a standard Cat5/Cat6 networing cable, it can typically extend RS232 communication up to 15–30 meters (50–100 feet), depending on cable quality and signal conditions.
8. What devices commonly use DB9 to RJ45 converter adapters?
Cisco router, Human Machine Interface device, barcode scanner, POS terminal, or serial printer,DAQ devices or embedded boards, monitoring systems (HVAC, energy meters, BMS).
9. Do I need special drivers to use D-sub 9 pin serial to RJ45 female adapter?
No. D-sub 9 pin serial to RJ45 female adapter is passive hardware, no need drivers.
10. How can I customize serial to network adapter pinout?
Most DB9 to RJ45 modular adapters have removable wires inside the housing. You can rearrange these wires to match your specific RS232 pin configuration.