Managing complex automation sequences in space-restricted panels is the primary role of the Mitsubishi Electric Q2ASCPU-S1, a high-performance compact CPU module designed for the MELSEC QnAS Series control platform. Engineered to deliver rapid instruction execution and extensive memory capacity, this processor handles demanding industrial applications requiring short cycle times and large recipe storage capacity within a compact footprint.
Key Features
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60k Steps Program Capacity: Supports large-scale control logic, complex algorithms, and extensive recipe management.
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High-Speed Processing: Achieves basic instruction execution speeds of 0.15 microseconds for rapid system response.
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Expanded I/O Control: Direct addressing and management of up to 1024 local and remote I/O points.
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Integrated Communication: Built-in RS-232C interface facilitates direct connection to HMIs, programming PCs, and peripheral devices.
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Backward Compatibility: Integrates seamlessly with existing MELSEC AnS series backplanes and specialized I/O modules.
Applications
- Multi-axis packaging and labeling machinery requiring high-speed synchronization.
- Automated material handling, sorting, and conveyor distribution networks.
- Water and wastewater treatment facility distributed control systems.
- Food and beverage batch processing lines with complex recipe configurations.
Technical Specifications
| Parameter |
Specification |
| Manufacturer |
Mitsubishi Electric |
| Model / SKU |
Q2ASCPU-S1 (Q2AS-CPU-S1) |
| Control Method |
Stored program repetitive operation |
| Program Capacity |
60k steps |
| I/O Points |
1024 points |
| Basic Instruction Execution Speed |
0.15 microseconds (LD instruction) |
| Internal Current Consumption (5 VDC) |
300 mA (0.3 A) |
| Communication Interfaces |
RS-232C (9-pin D-sub), Programming Port |
| Memory Type Support |
RAM, ROM, EEPROM (via optional memory cassette) |
| Operating Temperature |
0 to 55 degC |
| Storage Temperature |
-20 to 75 degC |
| Country of Origin |
Japan |
| Shipping Weight (Calculated) |
0.45 kg |
| Package Dimensions (Calculated) |
150 x 110 x 45 mm |
Connections and Interfaces
| RS-232C Pin |
Signal Name |
Description |
| Pin 1 |
CD |
Carrier Detect |
| Pin 2 |
RXD |
Receive Data |
| Pin 3 |
TXD |
Transmit Data |
| Pin 4 |
DTR |
Data Terminal Ready |
| Pin 5 |
SG |
Signal Ground |
| Pin 6 |
DSR |
Data Set Ready |
| Pin 7 |
RTS |
Request to Send |
| Pin 8 |
CTS |
Clear to Send |
Empirical Engineering Insights
Alternative Models & Compatibility
The Q2ASCPU-S1 acts as a direct, high-capacity upgrade to the standard Q2ASCPU (which is limited to 28k steps). It shares identical physical dimensions and backplane mounting configurations. When migrating from older AnS series CPUs (such as the A1SCPU or A2SCPU), the Q2ASCPU-S1 allows you to retain your existing I/O chassis and modules, though program conversion via GX Developer or GX Works2 is required to map the updated instruction set and register structures.
Application Pitfalls & Engineering Notes
This CPU utilizes volatile RAM for its primary program execution. To prevent program loss during extended power shutdowns, a functional backup battery (A6BAT) must be maintained. If the "BAT.ERR" LED illuminates on the front panel, the battery must be replaced within 7 days. For critical applications, it is highly recommended to install an optional non-volatile memory cassette (such as the Q2MEM-8MBA) to store a permanent backup of the parameters and logic.
Commissioning & Wiring Tips
When establishing serial communications via the built-in RS-232C port, ensure that your cable configuration matches the handshaking requirements of your connected device. If using a standard 3-wire connection (TXD, RXD, SG), you must jumper pins 7 (RTS) and 8 (CTS) together on the CPU side to prevent communication timeouts. When configuring GX Developer, select "Q2AS(H)" as the PLC type to enable full instruction compatibility during download.
Installation Guidelines
CRITICAL WARNING
Risk of electrical shock and equipment damage. Completely de-energize the main power supply to the base unit and all associated external I/O circuits before mounting or removing the CPU module. Failure to do so can cause backplane bus damage or CPU malfunction.
1
Align the hook at the bottom of the CPU module with the module locating hole on the base unit.
2
Push the top of the module firmly toward the base unit until it snaps securely into the upper latching mechanism.
3
Secure the module to the base unit by tightening the module fixing screw (M3 x 12) to a torque of 0.36 to 0.48 N-m.
4
Insert the memory cassette and connect the backup battery connector before applying system power.