Mitsubishi Q2ASHCPU PLC System

The Mitsubishi Q2ASHCPU is a high‑performance CPU module for the Melsec Q series programmable logic controllers. This configuration includes the Q2ASHCPU main unit, an A1SX42 32‑point DC input module, an A1SY42 32‑point DC output module, a QC24‑R2 communication module (RS232C), and an A1SD75P2‑S3 positioning module. Together, they form a complete control system for demanding automation applications requiring discrete I/O and precise motion control.

Q2ASHCPU – CPU Specifications

The Q2ASHCPU features a 32‑bit RISC processor with program capacity of 28k steps. Execution speed: 0.15 µs per basic instruction (LD). Built‑in RAM: 128 KB, expandable with memory card. The CPU supports 4096 I/O points (max) and 2048 internal relays. Communication ports: RS232 (programming) and RS422 (peripheral). Power supply: 5V DC from backplane (consumption 0.5 A). Operating temperature 0‑55°C. Dimensions: 98 mm H x 27.4 mm W x 89 mm D. The CPU is compatible with Melsec Q series base units and can control up to 64 modules.

A1SX42 – Digital Input Module

The A1SX42 is a 32‑point DC input module (24 V DC, sink/source compatible). Each input channel has an LED indicator and optical isolation. Rated input voltage: 24V DC (20.4‑26.4V), input current 5 mA typical. Response time: 10 ms (selectable 1.5/5/10/20/70 ms). The module connects to the Q series backplane via a dedicated connector. Power consumption from 5V backplane: 70 mA. Dimensions: 90 mm H x 54 mm W x 110 mm D. Suitable for reading sensors, switches, and limit switches.

A1SY42 – Digital Output Module

The A1SY42 provides 32 transistor sink outputs (24 V DC, 0.1 A per point). Outputs are protected against short circuit (current limit) and have built‑in surge suppression. Common voltage: 24V DC (20.4‑26.4V). Response time: OFF to ON = 1 ms, ON to OFF = 1 ms. The module includes LED indicators for each output and a common fuse. Consumption from 5V backplane: 120 mA. Dimensions same as A1SX42. Ideal for controlling solenoids, relays, and indicator lamps.

QC24‑R2 – Communication Module

The QC24‑R2 is a two‑port RS232C interface module for Melsec A or Q series. It supports MC protocol (MELSEC communication) for connection to HMIs, PCs, or other PLCs. Baud rates: 300 to 115.2 kbps. One port is dedicated for programming (via GX Developer), the second for general purpose communication (Modbus RTU master/slave possible with dedicated programming). Isolation: 500V between ports and backplane. The module consumes 150 mA from 5V bus.

A1SD75P2‑S3 – Positioning Module

The A1SD75P2‑S3 is a two‑axis positioning module for open‑loop control of stepper or servo drives. It outputs pulse trains (up to 200 kpps) with direction/sign signals. Supported functions: linear interpolation (2 axes), circular interpolation, continuous path control, and back‑lash compensation. The module has 4 digital inputs (for limit switches) and 4 outputs (servo ready, in position). Programming is done via dedicated GX Configurator‑PT software. Axis control can be initiated from the PLC CPU using FROM/TO commands.

System Integration

All modules mount onto a Mitsubishi Q series base rack (e.g., Q38B, Q312B). The Q2ASHCPU must be placed in slot 0; I/O modules occupy subsequent slots. Wiring is via removable terminal blocks (A1SX42/A1SY42 require 40‑pin connector – A6CON1). The QC24‑R2 connects via 9‑pin D‑sub. The positioning module uses a 50‑pin connector for drive interface. Configuration is performed using Mitsubishi GX Works2 or GX Developer. The system supports cyclic I/O refresh and interrupt handling.

Applications

Typical applications include packaging machinery (with positioning for cut‑to‑length), assembly lines (I/O monitoring and control), and specialized automation in automotive and electronics industries. The combination of discrete I/O (64 points) and two‑axis positioning provides a compact solution for small to medium machines.

Environmental and Compliance

All modules are CE marked and RoHS compliant. Operating temperature range 0‑55°C, humidity 10‑90% non‑condensing. The units are rated IP20 and must be installed in a control cabinet. Vibration resistance: 2g (10‑55 Hz).

Conclusion

This Mitsubishi Q2ASHCPU‑based system offers a complete control solution with digital I/O, serial communication, and two‑axis positioning. It is well‑suited for retrofitting legacy machines or building new automation cells where motion and discrete control are both required.