MITSUBISHI ELECTRIC MELSEC A series Programmable Controller

The MITSUBISHI ELECTRIC MELSEC-A series PLC (AnS) hardware user manual covers CPU models such as A1S (S1)/A2S (S1)/A1SH/A2SH/A2ASCPU, detailing safety specifications, environmental specifications, module parameters, installation wiring, fault safety, maintenance, error codes, etc. It specifies the electrical specifications of power/input/output/hybrid I/O modules, specifies EMC/low-voltage instruction installation requirements, provides fault safety circuit design and battery replacement, daily/regular inspection procedures, and provides a complete error code table for comparison with CPU model differences. It is an authoritative guidance document for hardware installation, debugging, and maintenance of this series of PLCs.

​Safety precautions (graded)

1. Danger level (DANGER)

External safety circuits (emergency stop, limit, interlock) must be constructed

Wiring/maintenance must be completely powered off

The protective grounding terminal (LG/FG) must be grounded

Non rechargeable battery, disassembly, heating, short circuit

Do not touch the terminals when powered on

2. Attention level (CAUTION)

Distance between control line and power line * * ≥ 100mm**

Terminal screw tightening torque: 59~118N · cm

Do not modify or disassemble modules

Disposal as industrial waste

General environmental specifications

Parameter indicators

Working temperature 0~55 ℃

Storage temperature -20~75 ℃

Working humidity 10~90% RH (no condensation)

Altitude ≤ 2000m

Pollution level 2

Overvoltage category II

Anti vibration range of 10~150Hz, 1G

15G impact resistance, 3 times/direction

Core module specifications

1. Power module (typical)

Model input voltage output allows for instantaneous power outage

A1S61P 100/200VAC 5VDC 5A ≤20ms

A1S62P 100/200VAC 5VDC 5A+24VDC 0.6A ≤20ms

A1S63P 24VDC 5VDC 5A ≤1ms

2. Input module (classification)

AC input: A1SX10EU (200VAC, 16 points)

DC input: A1SX40 series (24VDC, 16/32/64 points)

AC/DC input: A1SX30 (12/24VAC/DC, 16 points)

Key parameters: response time of 0.1~35ms, withstand voltage of 500~2830VAC

3. Output module (classification)

Type, model, load response time

Relay A1SY10 2A/point, 240VAC 10ms → 12ms

Controllable silicon A1SY22 0.6A/point, 200VAC 1ms

Transistor A1SY40 0.1A/point, 24VDC 2ms

4. Hybrid I/O modules

A1SH42:32 in 32 out (DC transistor)

A1SX48Y18: 8 inputs and 8 outputs (relay)

A1SX48Y58: 8 inputs and 8 outputs (transistor)

Installation specifications

Installation environment: It must be installed in a control cabinet with an IP54 or higher rating

EMC requirements

Control cabinet metal material, multi-point grounding

Shielded wire with large area grounding, cable with magnetic ring added

Separation of power and signal lines

Module installation

The bottom buckle is securely fastened to the base

Up and down spacing * * ≥ 30mm * *, both sides * * ≥ 50mm**

DIN rail: TH35-7.5, screw spacing ≤ 200mm

grounding

LG/FG use * * ≥ 2mm ² * * wire for short distance grounding

Large area connection of shielding layer to cabinet

Wiring specifications

Power wiring

First connect the PLC power supply, then connect the load power supply

It is prohibited to connect multiple power supplies in parallel to supply power to the same module

I/O wiring

Input: DC 24V, COM common terminal

Output: Relays can be AC/DC, transistors only DC

Wire diameter: 0.75~1.25mm ², torque 59~88N · cm

communication wiring

RS-232C: Cable ≤ 15m

Shielded wire single ended grounding to reduce interference

Fault safety design

mandatory requirement

External emergency stop, limit, forward and reverse interlock

Key outputs are monitored separately

Output circuit with fuse

power-up sequence

Power supply for PLC

Supply power to the load

start operation

Program driver output

Maintenance and upkeep

1. Daily inspection

The base, module, and wiring are not loose

POWER/RUN/ERROR indicator lights are normal

Input/output LED status is normal

2. Regular inspection (6-12 months)

Environmental temperature and humidity, non corrosive gases

Power supply voltage, terminal fastening, dust prevention

Battery status (M9006/M9007)

3. Battery replacement

Battery model: A6BAT

Low voltage alarm: M9006/M9007 action

Replacement requires power-off operation

Error code (core)

Error code, error name, reason handling

10 instruction code error program including unable to decode instruction correction program

11 Parameter Error Parameter Area Damaged Reset Parameters

22 WDT Error Scan Timeout Optimization Program

Unit 31 verification error module plug-in/model mismatch reinstallation

32 fuse blown, output short circuit replaced fuse

70 battery error, low voltage/disconnection, replace A6BAT

Appendix Core

CPU difference

A1SHCPU: speed 0.33 μ s, 2048 I/O points, supports CC Link

A2SHCPU: Speed 0.25 μ s, Memory 64KB

A2ASCPU: speed 0.15~0.20m/step, memory 256KB

CE compatible module

CPU：A1SH/A2SH

Power supply: A1S61PEU/62PN

I/O: A1SX10EU, A1SY10EU, etc

CC Link specific instructions: RLPA/RRPA/RIRD/RIWT, totaling 11

Key issues

Question: What external circuits must be included in the fail safe design of MELSEC-A series PLCs? What are the mandatory requirements for the power on sequence? 

Answer: It must include emergency stop circuit, limit position protection, forward and reverse interlock, and critical output monitoring circuit; The strict power on sequence is: ① supplying power to the PLC host → ② supplying power to external loads → ③ starting the operation switch → ④ driving the output device by the program to prevent erroneous output.

Question: What are the three types of input/output modules for A-series PLC? What are the typical models, maximum load, and response speed of each? 

Answer: The three types are: ① Relay output (A1SY10, 2A/point, 240VAC, 10 → 12ms); ② Controllable silicon output (A1SY22, 0.6A/point, 200VAC, 1ms); ③ Transistor output (A1SY40, 0.1A/point, 24VDC, 2ms).

Question: How to determine the battery alarm of A-series PLC? What are the replacement requirements? What are the items included in daily and regular inspections? 

Answer: The low voltage of the battery is indicated by the M9006/M9007 alarm; A6BAT must be used, power off for replacement. Daily inspection: module fixation, wiring, LED status; Regular inspection (June to December): environmental temperature and humidity, power supply voltage, terminal torque, battery status, dust and corrosion prevention.