Technical Overview

The NFAP135-S00 is a high-speed pulse input module for the Yokogawa CENTUM VP DCS. It is optimized for frequency-generating field devices such as flowmeters, encoders, and tachometers, offering fast, precise pulse counting and frequency measurement. The module’s channel-to-channel isolation ensures electrical robustness, protecting the DCS backplane and other I/O channels from faults or surges.

Detailed Specifications

Operational Capabilities

• High-speed acquisition: 2 ms refresh cycle for fast loop control

• Noise suppression: Built-in filter eliminates mechanical contact chattering

• Versatile powering: Supplies 2-wire and 3-wire transmitters directly

• Electrical robustness: Channel-to-channel isolation prevents faults from propagating

• Suitable for totalization and instantaneous measurement in chemical, oil & gas, and utility sectors

Technical FAQ

Can this module measure both totalized flow and instantaneous flow?

• Yes. NFAP135-S00 provides pulse counts for totalization and frequency data for instantaneous flow rate simultaneously.

What is the benefit of channel-to-channel isolation?

• Prevents ground loops and ensures that a fault on one sensor does not affect other channels or the DCS system.

Does this module support “Dry Contact” sensors?

• Yes. Internal 12V or 24V pull-up resistance allows monitoring of mechanical dry contacts or open-collector transistor outputs.