Mitsubishi A1S68AD MELSEC‑A 8‑Channel Analog Input Module

Mitsubishi Electric A1S68AD is an analog‑digital converter module for the MELSEC‑A series PLC system. Converts voltage (–10 to +10 V DC) or current (0–20 mA DC) signals from field sensors into 16‑bit signed binary digital values for process monitoring and control. 8 channels per module. Photocoupler isolation between input terminals and PLC power supply. 20‑point screw terminal block. Intended for legacy MELSEC‑A system maintenance and spare part replacement.

Applications:

• Analog signal acquisition from pressure, flow, level and temperature sensors

• Process monitoring and control in industrial automation systems

• Data acquisition for legacy MELSEC‑A based configurations

• Maintenance and spare part replacement for existing AnS/QnAS series installations

Core Specifications:

• Number of inputs: 8 analog input channels

• Input signal ranges (configurable per channel):

  • Voltage: –10 to 0 to +10 V DC (input resistance: 1 MΩ)

  • Current: 0 to +20 mA DC (input resistance: 250 Ω)

• Absolute maximum input: Voltage ±35 V, Current ±30 mA

• A/D conversion resolution: 12‑bit (0 to +4000 for 0‑10 V, –2000 to +2000 for –10 to +10 V)

• Maximum resolution: 2.5 mV for 0‑10 V, 5 mV for –10 to +10 V, 5 µA for 0‑20 mA

• Overall accuracy: ±1% of full scale at 25 °C

• Conversion speed: 0.5 ms per channel (1 ms for all 8 channels when averaging processing is used)

• Isolation: Photocoupler isolation between input terminals and PLC power supply (no isolation between channels)

• External connection: 20‑point screw terminal block

• Applicable wire size: 0.75 to 1.5 mm²

• Number of occupied I/O points: 32 (I/O assignment: special 32 points)

• Dimensions (W × H × D): 37.5 mm × 130 mm × 108 mm (approx.)

• Weight: 0.27 kg

• Operating temperature: 0 °C … 55 °C

System Integration:

• Belongs to the Mitsubishi Electric MELSEC‑A series.

• Installs into MELSEC‑A series main base unit slots via the A series backplane bus.

• Compatible with MELSEC‑A series CPU modules and AnS/QnAS series systems.

• For detailed installation, wiring and module settings, refer to the A1S68AD User’s Manual (Hardware).

Product Status:
Discontinued. Mitsubishi Electric has discontinued the MELSEC‑A series. Available as a spare part for maintaining existing MELSEC‑A and AnS/QnAS based automation systems while stocks permit. Recommended replacements for migration to Q series are Q68ADV (voltage) or Q68ADI (current). For migration to L series, recommended replacements are L60ADVL8 (voltage) or L60ADIL8 (current).

Standards & Compliance:
Refer to manufacturer official documentation for detailed certification and compliance information.