B&B Electronics CL238 RS-232 to Current Loop Serial Converter

The B&B Electronics CL238 is a passive RS-232 to 20mA current loop converter designed for reliable serial data communication between RS-232 devices and current loop equipment. Current loop interfaces are commonly found in older industrial terminals, printers, and control systems, and the CL238 provides a simple, cost-effective bridge between modern RS-232 serial ports and these legacy devices.

Key Features:

• Converts RS-232 signals to 20mA active current loop and vice versa
• Passive design — powered directly from the RS-232 port, no external power supply required
• Compatible with standard RS-232 serial ports (DB9 or DB25)
• Supports full-duplex communication
• Compact, inline form factor for easy installation
• Suitable for industrial and legacy equipment integration

The CL238 is ideal for engineers and technicians needing to interface modern computers or serial devices with older current loop peripherals such as teletype terminals, legacy industrial controllers, and serial printers. Its passive, self-powered design eliminates the need for additional cabling or power adapters, making installation straightforward.