Mitsubishi MELSEC-A Series Modules: A1SY10 Digital Output Local Unit Module

Technical Dossier

Product Details And Specifications

Mitsubishi MELSEC-A Series Technical Notes

The Mitsubishi MELSEC-A Series is a modular programmable logic controller (PLC) platform developed by Mitsubishi Electric and deployed extensively across global heavy industry sectors including petrochemical plants, nuclear power facilities, steel mills, and oil refineries. Introduced in the early 1980s, the A Series established a standardized backplane bus architecture that enabled scalable I/O expansion through local and remote unit configurations. Its installed base remains substantial in legacy process control environments where system continuity and long-term spare parts availability are primary operational requirements. The A1S sub-family — compact, rack-mounted modules sharing a unified bus standard — represents the most widely deployed variant within this series globally.

The Evolution of MELSEC-A Series Architecture

The MELSEC-A Series architecture progressed through three distinct generations. The original A-Series (A2A, A3A) used a parallel bus backplane with proprietary inter-module communication, supporting up to 256 I/O points per base unit. The A1S sub-series introduced a compact form factor with a 5-slot and 9-slot base unit configuration, retaining full bus compatibility with the parent series while reducing panel footprint. Communication expansion was achieved through dedicated link modules (A1SJ71AP23Q, A1SJ71QLP23) supporting MELSECNET/B and MELSECNET/10 topologies.

Q: How are RFQ terms confirmed?
A: Quantity, required condition, documentation needs, destination and sourcing route are confirmed during RFQ review before quotation.

MELSEC-A Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly sourced modules within the MELSEC-A Series. Each entry reflects a distinct functional role within the system architecture.

CPU Modules

Digital Input (DI) Modules

A1SX10: 16-point DC input module, 24VDC, sink/source compatible, 10ms response time.
A1SX20: 16-point DC input module, 12/24VDC, isolated commons, 10ms response time.
A1SX30: 16-point AC input module, 100/110VAC, 50/60Hz, optically isolated inputs.
A1SX40: 16-point DC input module, 24VDC, high-speed 1ms response, interrupt-capable.

Digital Output (DO) Modules

A1SY10: 16-point transistor output module, 12/24VDC, 0.5A per point, sink output type, local unit configuration. This is the primary SKU for this listing.
A1SY18A: 8-point transistor output module, 12/24VDC, 0.5A per point, source output type.
A1SY28A: 16-point transistor output module, 24VDC, 0.1A per point, high-density source output.
A1SY40P: 16-point transistor output module, 12/24VDC, 0.5A per point, sink type with surge protection.
A1SY60: 16-point relay output module, 240VAC/24VDC, 2A per point, mechanical relay contacts.

Analog Modules

A1S62DA: 2-channel analog output, 12-bit resolution, 0–10V / 4–20mA selectable per channel.
A1S64AD: 4-channel analog input, 12-bit resolution, voltage/current input, high-speed conversion.

Communication & Network Modules

A1SJ71AP23Q: MELSECNET/B master/local station module, coaxial bus topology, 10Mbps.
A1SJ71QLP23: MELSECNET/10 optical loop module, 10Mbps, up to 64 stations per network.

Quality Control for the MELSEC-A Series Range

MELSEC-A Series modules use a parallel backplane bus with strict timing and voltage tolerance requirements. Quality verification for these modules requires hardware-level testing beyond standard power-on checks. DriveKNMS applies the following test protocol to all A-Series units: