Black Box Corporation IC455B Current Converter

Black Box IC455B is a legacy RS-232-to-RS-422/RS-449 interface converter that translates single-ended RS-232 serial data into differential RS-422/RS-449 signals, enabling longer cable runs and improved noise immunity when connecting legacy equipment to a balanced serial network. Identified by part number IC455B, the unit weighs 1.84 lb and was manufactured by Black Box Corporation. The device is listed as discontinued by the manufacturer. In historical reference material, the IC455B is described as an interface/converter (often noted as GJ-IC455B) used with Grass Valley equipment such as the Jupiter CM-4400 family, illustrating its role in bridging RS-232 to RS-422 in broadcast and telecom environments. Availability today is typically through surplus channels and used-stock listings (for example, Radwell and other marketplaces) offering used or refurbished units.