Mitsubishi Alpha XL Alarm Modem M20 Expansion Module

The Mitsubishi Alpha XL alarm memory modem is an intelligent communication module designed for Mitsubishi Melsec FX series compact PLCs and Alpha XL micro controllers. This modem provides autonomous communication capabilities, including 56k data transmission, SMS text messaging, email sending, and fax communication. The M20 expansion module configuration enables remote monitoring and alarm notification for distributed automation applications without additional controller programming burden.

Technical Overview

The Mitsubishi Alarm Modems are autonomous communication controllers equipped with their own 32-bit microprocessors and up to 66 megabytes of Flash memory. This dedicated processing architecture ensures that the modem handles all data communication tasks independently, placing no additional load on the host PLC or controller. The modem is pre-configured with controller protocols, eliminating the need to load drivers in the controller or make controller program changes for basic communication functionality.

The M20 expansion capability supports connection to Alpha XL controllers via the COM ports, enabling the modem to monitor controller values, input and output states, and alarm conditions. The modem can store up to 100 addresses, message texts, controller values, and alarms in its non-volatile memory. The system supports multi-level alarm plans, allowing users to prioritize and route alerts based on severity or message content.

Key Features

• 56k modem communication capability

• Autonomous 32-bit microprocessor with 66 MB Flash memory

• SMS text messaging, email, and fax communication support

• Compatible with Melsec FX series PLCs and Alpha XL controllers

• M20 expansion module configuration

• Stores up to 100 addresses, messages, and alarm conditions

• Pre-configured with controller protocols

• MX Alarm Modem Editor configuration software

• Caller number identification for security

• DIN rail mounting with standard serial cable connection

• Remote maintenance access to entire controller program

Configuration and Software

The modem is configured using the MX Alarm Modem Editor software, a user-friendly application that allows entry of alarm messages, telephone numbers, email addresses, and other operational data. The editor enables users to link message texts to controller values and target addresses to alarms with simple mouse-click operations. Message text length is not limited, providing flexibility for detailed alert descriptions. The software supports multi-level alarm plans, enabling sophisticated notification strategies for different operational scenarios.

Remote Monitoring Capabilities

The Alpha XL alarm modem provides comprehensive remote monitoring functionality, enabling users to access distributed automation systems from any location. The modem can send data by SMS text messaging, email, or fax, and can receive commands via SMS. This capability is particularly valuable for facilities with geographically dispersed equipment, such as pumping stations, HVAC systems, or remote production lines. The modem also provides access to the entire controller program for remote maintenance functions, allowing authorized personnel to diagnose and resolve issues without on-site visits. Caller number identification prevents unauthorized dial-ins, with additional security layers available for sensitive installations.

Applications

Typical applications for the Mitsubishi alarm modem include building services monitoring for cooling, heating, and air conditioning systems; tank storage facilities for liquid level monitoring; pump and water station management; container transporters; and other specialized vehicles. The modem is also suitable for any industrial application requiring remote alerting or maintenance access to distributed controllers not connected via a control network. The autonomous design ensures that the modem continues to function even if the host controller is performing other tasks.

Integration with Mitsubishi Controllers

The modem connects to Alpha XL controllers via the COM ports, with RS232 interface for basic connectivity and RS485/422 for two-wire and four-wire bus systems. The Alpha XL controller itself is an expanded version of the Alpha series, featuring extra large backlit LCD display, tripled program capacity to 200 function blocks, 15 new user-specific function blocks, integrated MMI functionality, and expanded operating temperature range. When combined with the alarm modem, the Alpha XL becomes capable of remote monitoring and alerting for distributed automation systems.

Conclusion

The Mitsubishi Alpha XL alarm modem with M20 expansion capability provides intelligent, autonomous communication for distributed automation systems. By handling messaging and remote access independently of the host controller, it enables cost-effective implementation of remote monitoring and maintenance services. For engineers deploying Mitsubishi FX or Alpha XL controllers in distributed or remote locations, this modem offers a practical solution for staying connected to their automation assets.