USB to RS-422/485 Isolated Converter with DB9 Male Connector
The BB-USO9ML4 USB to RS-422/485 converter is engineered for industrial automation professionals, system integrators, and IT technicians who need reliable serial communication on modern USB-only computers. This isolated RS-422/485 converter eliminates the need for legacy serial ports while maintaining 2 kV galvanic isolation to protect sensitive equipment from ground loops and electrical noise. Whether you're connecting legacy industrial devices, PLC systems, or SCADA networks to contemporary PCs, this DB9 male converter delivers enterprise-grade performance in a compact form factor. Bus-powered operation and plug-and-play USB 2.0 connectivity make it the ideal solution for field service, maintenance, and integration projects.
Key Features
- 2 kV galvanic isolation protects equipment from electrical interference and ground loops
- Supports 2-wire RS-485 and 4-wire RS-422/485 communication modes
- DB9 male serial connector for direct legacy device integration
- High-retention USB 2.0 Type B female connector ensures secure connections
- Bus-powered operation—no external power supply required
- Serial data rates up to 460.8 Kbps for real-time industrial applications
- LED indicators for transmit and receive activity monitoring
- Compact design fits tight installation spaces
- Plug-and-play USB connectivity with standard driver support
Technical Specifications
| Specification |
Details |
| Manufacturer |
B+B SmartWorx |
| Part Number |
BB-USO9ML4 |
| Interface Type |
USB to RS-422/485 Isolated Converter |
| Isolation Level |
2 kV galvanic isolation |
| Serial Connector |
DB9 male |
| USB Connector |
Type B female, high-retention |
| Communication Modes |
2-wire RS-485, 4-wire RS-422/485 |
| Maximum Data Rate |
460.8 Kbps |
| Power Supply |
Bus-powered from USB host |
| Status Indicators |
LED transmit and receive activity lights |
| USB Standard |
USB 2.0 |
Frequently Asked Questions
What is a USB to RS-422/485 converter used for?
A USB to RS-422/485 converter enables modern computers without legacy serial ports to communicate with industrial equipment, PLCs, sensors, and SCADA systems that use RS-422 or RS-485 serial protocols. The BB-USO9ML4 adds this critical connectivity to USB-only PCs instantly.
Why is 2 kV isolation important in an isolated RS-485 converter?
Galvanic isolation prevents ground loop noise and electrical interference from damaging sensitive computer equipment or corrupting data. The 2 kV isolation in this isolated converter protects your PC and industrial devices in harsh electrical environments common in manufacturing and automation facilities.
Can the BB-USO9ML4 work with both RS-422 and RS-485 devices?
Yes. This RS-422/485 converter supports both 2-wire RS-485 and 4-wire RS-422/485 communication modes, making it compatible with a wide range of industrial serial devices and legacy equipment.
Is external power required for the BB-USO9ML4?
No. The converter is bus-powered directly from the USB host, eliminating the need for external power supplies and simplifying installation in field and mobile applications.
