YOKOGAWA NFAR181-S00 CENTUM VP RTD Input Module

Configured for resistance temperature sensor data acquisition in CENTUM VP systems, the YOKOGAWA NFAR181-S00 (NFAR181 RTD Input Module) provides direct physical/electrical execution. This 16-channel unit converts resistance inputs from 3-wire and 4-wire RTD field assemblies across an input resistance range of 0 to 400 ohm directly into digital process variables.

Hardware Specifications

Process Control & Channel Isolation Architecture

The module incorporates channel-to-channel isolation circuits to prevent common-mode voltage interference from corrupting temperature measurements across the 16 signal inputs. Cold junction compensation (CJC) algorithms run parallel to internal analog-to-digital conversion stages, delivering high-accuracy data conditioning. Designed for continuous field control station operation, the module interfaces with 4-20 mA HART loop protocol diagnostic layers and FOUNDATION Fieldbus network segments to maintain signal integrity across critical loops.

Frequently Asked Questions

Q: Does the NFAR181-S00 module support online replacement during system operation?

A: Yes. Technicians can replace the module under power when mounted in a compatible Yokogawa node unit without interrupting Vnet/IP system bus communications or surrounding I/O module signals.

Q: Can 3-wire and 4-wire RTD sensors be wired concurrently on different channels of the same NFAR181-S00 module?

A: Yes. Each of the 16 isolated channels accepts independent software configuration for either 3-wire or 4-wire RTD wiring setups.

Q: How does the module handle a broken sensor wire or open-circuit condition?

A: The internal diagnostic circuit detects resistance values exceeding the 0 to 400 ohm threshold and sends immediate open-circuit failure flags directly to the DCS controller.

Field Installation Guidelines

Mount the module securely into its designated slot on the Yokogawa node unit interface backplane, ensuring the locking latches snap into position. Connect field sensor conductors using shielded twisted-pair cables designed for low-resistance RTD loops. Route all signal wiring through dedicated low-voltage wire trays, maintaining physical separation from high-voltage AC lines and variable frequency drive cables. Ground all cable drain wires at a single protective earth point on the cabinet grounding rail to eliminate potential ground loop interference.