The Yokogawa NFAR181-S00/R8S0, also cataloged as the NFAR181 RTD Input Module, operates as a dedicated hardware component for 12-channel temperature signal acquisition within distributed control system platforms.

Hardware Specifications

Process Control and Channel Isolation

The NFAR181 module provides high-density temperature sensing through 12 galvanically isolated input channels. This architecture ensures effective channel-to-channel isolation, preventing common-mode noise and ground loops from affecting measurement precision in distributed control environments. The module facilitates accurate RTD signal processing with minimal temperature drift, capped at 30 ppm/deg C. It is optimized for integration with 4-wire, 3-wire, or 2-wire RTD configurations, provided the total resistance per wire does not exceed 40 ohms.

Frequently Asked Questions

Q: Is the NFAR181-S00/R8S0 compatible with hot-swapping under power?

A: Yes, this module supports hot-swapping within the N-IO system environment, allowing for replacement without interrupting the communication of other modules on the same node.

Q: What is the significance of the 1500 V AC withstanding voltage specification?

A: This rating defines the electrical isolation barrier between the field input terminals and the internal system backplane, protecting the controller circuitry from high-voltage transients or surges originating from the field side.

Field Installation Guidelines

• Ensure the module is securely latched into the dedicated base plate to maintain electrical contact with the backplane bus.
• Use shielded twisted-pair cabling for all RTD inputs; ensure the cable shield is grounded at the instrument or cabinet ground bar to minimize electromagnetic interference.
• Verify that the wire resistance for each channel remains below the 40 ohms limit to prevent measurement bias.
• Maintain a clean environment free of conductive dust when accessing terminal blocks to prevent accidental shorts across the 12 input channels.