Yokogawa AAR181-S50 S2 RTD Input Module

• Brand
  Yokogawa
• Model
  AAR181-S50 S2
• Product Name
  RTD Input Module
• Place of Origin
  Japan
• HS Code
  8537.10.90
• Dimensions
  107.5 mm × 32.8 mm × 130 mm
• Weight
  0.2 kg
• Operating Temperature
  −10 °C to +60 °C
• Storage Temperature
  −20 °C to +70 °C
• Power Supply
  ±5 V
• Warranty
  12 month
• Product Status
  New and original

Yokogawa AAR181-S50 S2

Input：

12-channel galvanically-isolated temperature analog input channels

Supports Pt100 / Pt1000 RTD sensors, covering 2-wire, 3-wire and 4-wire wiring modes

Accepts multiple thermocouple types including K, J, T, and low-level mV analog signals

Maximum allowable input voltage: ±5V

RTD excitation measurement current: 1 mA per channel

Adopts independent channel-to-channel galvanic isolation design

Embedded sensor burnout detection for temperature measuring loops

Isolation withstand voltage: 1500V AC for 1-minute between field side and system side

Output：

No physical analog output terminals on module hardware

Converts raw analog temperature signals from field sensors into standardized digital data

Transmits digital temperature process values and channel diagnostic status to CENTUM VP / ProSafe-RS FCS over FIO backplane bus

Sends multi-type channel fault alarm messages to DCS controller

  Open-circuit loop failure

   Sensor burnout fault

  Signal over-range abnormality

Yokogawa AAR181-S50 S2 Troubleshooting

Module FAIL LED lights solid red

  Root cause: Severe module hardware malfunction; abnormal backplane power supply; firmware incompatibility with FCS controller.

  Action: Inspect 5VDC back-plane power of FIO rack; confirm firmware compatibility for CENTUM VP / ProSafe-RS; execute hot-swap operation with qualified spare module.

 Module FAIL LED blinks and single-channel alarm activates

   Root cause: Field wiring defect; damaged temperature sensor; mismatched wiring mode setup in software.

  Action: Check RTD / thermocouple cables for open-circuit, short-circuit and loose terminal contacts; ensure software wiring selection (2-wire /3-wire /4-wire) conforms to actual field cabling; perform sensor burnout inspection.

Abnormal or drifting temperature measurement values

  Root cause: Incorrect sensor type configuration; electromagnetic interference from field cables; improper shield grounding; deviation of loop resistance.

  Action: Cross-check configured sensor type (Pt100, Pt1000, K/J/T thermocouple) against physical field device; route signal cables away from high-power cables; apply single-end shield grounding at DCS cabinet side; measure practical field loop resistance.

Sensor burnout alarm is triggered

  Root cause: Open-circuit of RTD or thermocouple loop; loose terminal connections; internal sensor failure.

  Action: Measure on-site sensor resistance value; fasten terminal block screws tightly; replace faulty temperature sensor.

Temperature channel reports over-range alarm

  Root cause: Mismatched measurement range configuration; excessive input signal; incorrect cold-junction compensation parameter for thermocouple.

  Action: Recheck engineering scale parameter settings; verify real output signal from field sensor; adjust and calibrate thermocouple cold-junction compensation.

Channel data fails to be uploaded to FCS controller

  Root cause: Missing or incorrect slot hardware configuration; back-plane communication breakdown; unfinished module initialization.

  Action: Validate hardware slot setup within Engineering Builder; perform FCS configuration re-download; allow 10-30 seconds for complete module initialization; examine FIO rack back-plane status.

Multiple channels show abnormal readings at the same time

  Root cause: Shared ground fault; defective cabinet grounding; fluctuating rack power supply.

  Action: Verify cabinet protective grounding condition; remove cross-channel common ground connections; monitor power supply stability of FIO rack.

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