B&B Electronics CL37 Current Loop to RS-232 Converter

The B&B Electronics CL37 is a passive current loop to RS-232 signal converter designed for interfacing legacy 20mA current loop serial devices with modern RS-232 equipment. It provides a reliable and cost-effective solution for connecting older industrial terminals, printers, and data acquisition devices to RS-232 ports without requiring an external power supply.

Key Features:

• Converts 20mA current loop signals to RS-232 voltage levels
• Passive design — draws power directly from the RS-232 port (no external power required)
• Compact inline form factor for easy installation
• Compatible with a wide range of industrial serial devices
• Supports both active and passive current loop configurations
• DB-37 connector interface

The CL37 is ideal for industrial automation, data acquisition, and legacy system integration applications where current loop serial communication must interface with standard RS-232 hardware.