Serial Converter Series
USB to RS485 Converter
The UD-25PL converts a computer USB port into an RS485 interface, enabling high-speed data transmission between a PC and peripherals or devices that communicate over RS485. It is powered entirely through the USB port and requires no external power supply.
- USB 2.0 compliant input with RS485 output through a D9 male connector
- Supports baud rates from 300 bps to 921.6 Kbps
- Configurable data parity: odd, even, or no parity
- 512 byte receive and 512 byte transmit buffers for reliable data handling
- Powered directly through the USB port, no external adapter needed
Max Resolution
1080p Full HD
Audio Input
Stereo Analogue
Output
Single HDMI
- In-house manufactured
- 24hr response
- 2,000+ clients served
Product Overview
What makes the UD-25PL
The UD-25PL is a USB to RS485 converter designed for high-speed data transmission between a computer system and peripherals or other devices that use an RS485 interface. The USB port on the PC is used as the input, and an RS485 interface through a D9 male connector is provided as the output.
Data communication on the UD-25PL can be configured with odd parity, even parity, or no parity, depending on the requirements of the connected RS485 device. The converter supports a wide baud rate range from 300 bps up to 921.6 Kbps, allowing it to work with both slow and high speed serial peripherals.
An X-On and X-Off handshake protocol is used for software based flow control, and the converter is equipped with a 512 byte receive buffer and a 512 byte transmit buffer to support reliable data handling during transmission.
The unit draws its power directly through the USB port, removing the need for a separate power adapter. Once the supplied driver is installed on a Windows PC, the UD-25PL appears as a Virtual COM Port, allowing standard serial communication software to interact with the connected RS485 device.
Input
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Key Features
Built for reliable USB to RS485 communication
A compact, bus powered converter that bridges a PC USB port with RS485 connected peripherals, with configurable data settings for dependable serial communication.
USB 2.0 Compliant Input
The converter connects to a PC through a standard USB 2.0 port, providing a straightforward way to add RS485 connectivity to computer systems without internal hardware changes.
- USB 2.0 compliant input port
- Appears as a Virtual COM Port after driver installation
RS485 Output via D9 Male Connector
Output is provided through a D9 male connector wired for RS485 communication, allowing direct connection to industrial controllers and serial peripherals.
- D9 male connector output
- Dedicated Data+ and Data- signal pins
Wide Baud Rate Support
The converter supports a broad baud rate range, allowing it to operate with both slow legacy serial equipment and high speed RS485 devices.
- Supported baud rate: 300 bps to 921.6 Kbps
Configurable Data Parity
Data parity can be set according to the requirements of the connected RS485 device, supporting flexible integration with different serial equipment.
- Bandwidth: up to 90 MHz (-3dB)
- Signal level: 1V peak-to-peak (supported range: 0.4V to 1.4V)
- 75-ohm impedance for accurate signal matching
X-On / X-Off Handshake Protocol
Software based flow control through the X-On and X-Off handshake protocol helps manage data flow between the PC and the connected RS485 device.
- X-On / X-Off handshake protocol supported
Buffered Data Transmission
Dedicated receive and transmit buffers support consistent data handling during communication between the PC and the connected RS485 device.
- 512 byte receive buffer
- 512 byte transmit buffer
- Powered through USB port, no external power supply required
Installation
Driver setup and Virtual COM Port configuration
The UD-25PL is intended for use with a PC running a Windows operating system. Installation involves connecting the converter, installing the supplied driver, and verifying the resulting Virtual COM Port before connecting the RS485 device.
01
Connect and Install the Driver
Plug the UD-25PL into the PC USB port using the USB cable. The driver installation begins automatically as soon as the unit is plugged in. Insert the CD provided with the kit and follow the on screen instructions until the message "MLU485 installed successfully" is displayed, then click OK. This installation is required only once, or after the driver has been uninstalled.
02
Verify the Virtual COM Port
Open the device manager and confirm that the Virtual COM Port has been installed. Check the properties of the port, such as the baud rate and buffer size, to ensure they match the requirements of the connected RS485 device.
03
Connect the RS485 Device
Connect the RS485 port on the UD-25PL to the target device using an appropriate cable through the D9 male connector. Once connected, communication between the PC and the external RS485 device can take place through the Virtual COM Port.
04
Driver Uninstallation
To remove the driver, run CYG_UNINSTALL from the CD provided with the kit. A display message screen will guide the process through complete uninstallation of the drivers.
Where the UD-25PL performs
Engineered for connecting a PC USB port to RS485 based equipment across industrial, retail, and communication environments.
Factory Automation
Connects PC based monitoring or control software to RS485 networked equipment on the factory floor, supporting data exchange between the computer and connected automation hardware.
Programmable Logic Controllers
Provides a USB based link between a computer and programmable logic controllers that use an RS485 interface, supporting programming, monitoring, and data exchange tasks.
Attendance Recording Systems
Links attendance recording terminals that communicate over RS485 to a host PC, allowing recorded attendance data to be retrieved and processed through the Virtual COM Port.
Barcode Reader Integration
Allows barcode readers fitted with an RS485 interface to communicate with a PC through a standard USB connection, supporting data capture in retail and warehouse environments.
Remote Data Transmission
Supports communication with remote terminals and remote data transmission setups where a PC needs to exchange data with field equipment over an RS485 link.
EPABX and Telecom Systems
Enables connection between a PC and EPABX equipment fitted with an RS485 interface, supporting configuration and data exchange tasks for telecom installations.
Full specification sheet
- Interface
- Data Communication
- Buffer
- Power
- USB Port Pin Description
- RS485 Output Port Pin Description (D9 Male)
- Operating System Support
- Kit Contents
Full specification sheet
- Interface
- Data Communication
- Buffer
- Power
- USB Port Pin Description
- RS485 Output Port Pin Description (D9 Male)
- Operating System Support
- Kit Contents
FAQs about the UD-25PL
What is the purpose of the UD-25PL?
The UD-25PL is a USB to RS485 converter designed for high-speed data transmission between a computer system, through its USB port, and peripherals or other devices that use an RS485 interface.
The UD-25PL is a USB to RS485 converter designed for high-speed data transmission between a computer system, through its USB port, and peripherals or other devices that use an RS485 interface.
Does the UD-25PL need an external power supply?
No. The UD-25PL draws its power directly through the USB port, so no separate power adapter is required for operation.
What baud rates does this converter support?
The UD-25PL supports baud rates from 300 bps up to 921.6 Kbps, covering both slower legacy devices and high speed RS485 equipment.
Which parity settings are available on the UD-25PL?
The converter can be configured with odd parity, even parity, or no parity, depending on the data format required by the connected RS485 device.
What operating system is required to use this converter?
The UD-25PL is designed to be used with a PC running a Windows operating system. The supplied driver installs a Virtual COM Port and USB Bridge for communication.
How is the driver installed for the UD-25PL?
Plug the UD-25PL into the PC USB port, insert the CD provided with the kit, and follow the on screen instructions until the message “MLU485 installed successfully” appears. This installation is required only once, or after the driver has been uninstalled.
How can I confirm the Virtual COM Port is working correctly?
Open the device manager on the PC and check that the Virtual COM Port has been installed. The properties of the port, such as baud rate and buffer size, can also be reviewed there to confirm correct configuration.
How do I uninstall the UD-25PL driver?
Run CYG_UNINSTALL from the CD provided with the kit. A display message screen will guide you through the complete uninstallation of the drivers.
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