Yokogawa ALR121 Serial Communication Module for CENTUM VP FIO/N-IO

Product Brief Description

The Yokogawa ALR121 is a 2-port RS-422/RS-485 serial communication module developed for Yokogawa CENTUM VP DCS FIO and N-IO systems. It serves as a serial gateway between the Field Control Unit (FCU) and third-party field devices, supporting reliable long-distance serial data transmission in industrial control cabinets. The module features robust EMC performance and optional ISA G3 environmental compliance for harsh industrial locations.

Product Functions

• Two independent RS-422 / RS-485 serial ports for connecting serial-based instruments and sub-systems
• Transmit and receive serial data between CENTUM VP FCS and external devices via ESB bus
• Support standard serial communication protocols for data acquisition and control command exchange
• Built-in hardware diagnostic function to detect communication errors and module status faults
• Optional ISA G3 version for environments with vibration, humidity and corrosive contaminants
• Available explosion-proof variant for installation in hazardous area control cabinets

Application Scenarios

• Oil & gas, refinery and petrochemical DCS serial instrument integration
• Power plant boiler auxiliary system serial device data collection
• Water treatment, pulp and paper factory serial sensor communication
• Connect weighing indicators, analyzers and flow computers to CENTUM VP
• Batch manufacturing and chemical plant third-party equipment data interconnection

Frequently Asked Questions