Mitsubishi A1SD71-S2 – Single-Axis Positioning Module | MELSEC-A Platform
Engineering Background: The A1SD71-S2 is a dedicated single-axis positioning module designed for Mitsubishi Electric’s MELSEC-A series programmable logic controller platform. It provides high-precision pulse output control for servo drives and stepper motor systems, enabling accurate point-to-point and continuous path positioning in demanding industrial environments.
Product Positioning: Targeted at OEM machine builders, system integrators, and maintenance engineers who require a reliable, drop-in replacement or expansion module for existing MELSEC-A infrastructure. The A1SD71-S2 is the enhanced (-S2) variant offering extended functionality over the base A1SD71, making it the preferred choice for applications demanding fine-tuned motion profiles.
Complete Technical Specifications
| Parameter | Specification |
|---|---|
| Model Number | A1SD71-S2 |
| Series / Platform | MELSEC-A Series |
| Manufacturer | Mitsubishi Electric Corporation |
| Module Type | Single-Axis Positioning Module |
| Control Axes | 1 axis |
| Output Method | Pulse train output (CW/CCW or PULSE/SIGN) |
| Max. Output Pulse Frequency | 200 kpps |
| Positioning Data Points | Up to 600 points |
| Control Modes | Position control, Speed control, Speed-position switching |
| Interpolation | Linear (single-axis) |
| External I/O Signals | DOG (near-home), STOP, FLS/RLS (limit switches), CLEAR |
| Manual Operation | JOG, MPG (manual pulse generator) input |
| Power Supply | DC 5 V (supplied from base unit) |
| Current Consumption | 0.55 A (5 VDC) |
| Operating Temperature | 0 °C to 55 °C |
| Storage Temperature | −20 °C to 75 °C |
| Humidity | 10 % to 90 % RH (non-condensing) |
| Vibration Resistance | 10–57 Hz: 0.075 mm; 57–150 Hz: 9.8 m/s² |
| Shock Resistance | 147 m/s², 3 times each direction |
| Weight | Approx. 0.4 kg |
| Compatible Base Units | A1S-series, A2-series, A3-series main base / extension base |
| Programming Tool | GX Developer / GPP-W (FROM/TO instructions) |
| Country of Origin | Japan |
Proven Application Environments
- CNC Machining Centers – Precise axis positioning for tool changers and worktable indexing
- Semiconductor Wafer Handling – Sub-micron repeatability requirements in clean-room environments
- Packaging Machinery – High-speed pick-and-place and film registration control
- Printing & Converting Lines – Register mark detection with speed-position switching
- Automated Assembly Lines – Multi-station indexing tables and rotary dial machines
- Textile & Winding Equipment – Tension-controlled winding with precise traverse positioning
- Injection Molding Machines – Ejector pin and mold-open/close position control
Engineering Advantages
- -S2 Enhanced Variant – Extended positioning data capacity (600 points vs. 300 on base model) and additional control modes versus the standard A1SD71
- 200 kpps High-Speed Output – Supports high-resolution servo drives without pulse loss at rated speed
- Flexible Homing Routines – DOG-type, data-set type, and stopper-type home position return methods
- Speed-Position Switching – Seamless transition from speed control to position control mid-motion for complex profiles
- Dedicated Buffer Memory – FROM/TO instruction access via CPU; no special function block required
- Compact Form Factor – Standard MELSEC-A slot width; no additional mounting hardware needed
- Long Field Life – Solid-state design with no mechanical wear components; MTBF >100,000 hours
System Architecture & Signal Flow
The A1SD71-S2 occupies one slot on any MELSEC-A main or extension base unit. The CPU communicates with the module via the A-bus backplane using FROM/TO buffer memory instructions. The module autonomously executes positioning operations once triggered, offloading motion management from the CPU scan cycle.
Typical Signal Flow:
- CPU writes positioning data (target position, speed, acceleration) to module buffer memory via TO instruction
- CPU issues start command via Y-device output
- Module generates pulse train → Servo amplifier → Servo motor encoder feedback
- Module reads encoder position via external feedback or pulse count; updates X-device status bits
- CPU reads completion flags and current position via FROM instruction
Compatible Servo Amplifiers: Mitsubishi MR-J2S, MR-J3, MR-E series; third-party amplifiers accepting pulse/direction or CW/CCW input.
Sourcing & Quality Verification
At Konmask.com, every A1SD71-S2 unit passes a documented 4-step verification protocol before shipment:
- Origin Traceability Check – Serial number and date code verified against Mitsubishi Electric production records where accessible; units with unverifiable provenance are rejected
- Physical Inspection – Label integrity, connector pin condition, PCB visual inspection for counterfeit indicators (re-marking, sanding, misaligned silkscreen)
- Functional Power-On Test – Module seated in MELSEC-A test rack; buffer memory read/write verified; pulse output confirmed on oscilloscope
- ESD-Safe Packaging – Anti-static bag + foam insert + double-wall carton; humidity indicator card included for long-haul shipments
Procurement Process
- Inquiry – Email [email protected] or call +0086 19859288691 with your required quantity and delivery timeline
- Quotation – Receive itemized quote with unit price, lead time, and shipping options within 24 business hours
- Order Confirmation – Purchase order or proforma invoice accepted; T/T, L/C, and PayPal available
- Quality Hold – Unit reserved and re-tested upon order confirmation
- Shipment – DHL / FedEx / UPS express or sea freight consolidation; tracking number provided same day as dispatch
- After-Sales – 12-month warranty against defects; technical support via email within 1 business day
Technical FAQ
Q: Is the A1SD71-S2 compatible with MELSEC-Q or iQ-R series base units?
A: No. The A1SD71-S2 is exclusively compatible with MELSEC-A series base units (A1S, A2, A3 main/extension bases). For Q-series, the equivalent module is the QD75D1.
Q: What is the difference between A1SD71 and A1SD71-S2?
A: The -S2 suffix denotes an enhanced version with doubled positioning data capacity (600 vs. 300 points), additional speed-position switching modes, and improved manual pulse generator (MPG) input handling.
Q: Can I use this module with a third-party servo drive?
A: Yes, provided the servo drive accepts pulse train input (pulse/direction or CW/CCW). Set the output mode in buffer memory to match the drive’s input specification.
Q: Do you provide the original Mitsubishi programming manual?
A: Yes. The A1SD71-S2 User’s Manual (IB-66544) PDF is available upon request with every order.
Q: What is the lead time for in-stock units?
A: In-stock units ship within 1–3 business days. For out-of-stock items, typical sourcing lead time is 2–4 weeks depending on global availability.
Q: How do I verify authenticity upon receipt?
A: Check the Mitsubishi Electric holographic label on the module side panel, verify the serial number format (format: XXXXXXXX), and confirm the PCB revision marking matches the -S2 specification sheet.
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Contact: [email protected] | +0086 19859288691


