Schneider Electric 172JNN21032 Processor Adapter

Schneider Electric 172JNN21032 is a TSX Momentum Serial Option Adapter that adds a dedicated Modbus serial port to a Momentum processor, enabling RS-232 or RS-485 communication for Modbus devices and HMIs. It must be used in conjunction with a Processor Adapter and cannot be installed directly on an I/O base; the option module mounts behind the CPU in Momentum systems to extend serial Modbus connectivity. This part was discontinued on June 21, 2022, and Schneider notes that Unity Momentum processors (171CBUxxxxx) embed most of these functions, with remaining stock typically handled through service/spare channels. When paired with compatible Processor Adapters, it provides a single Modbus port on the option adapter; however, some processor configurations (e.g., certain 171 CCS/CCC adapters) disable the Modbus port on the option adapter. This legacy module is commonly referenced in older Momentum manuals and supplier catalogs and remains relevant for retrofits or maintenance of existing Momentum installations.