Yokogawa AAP135-S00 Pulse Input Module

Technical Dossier

Product Details And Specifications

Yokogawa AAP135 Series Technical Notes

The Evolution of AAP135 Architecture

The AAP135 module family was introduced as part of Yokogawa's CENTUM CS 3000 R3 platform in the early 2000s, designed to replace earlier pulse counting cards that lacked digital diagnostics and hot-swap capability. The original AAP135 base variant supported single-channel pulse input with a maximum frequency ceiling suited to standard turbine meter applications. Subsequent suffix variants — including the AAP135-S00 — introduced factory-configured option sets covering input impedance selection, pulse width filtering, and contact input compatibility, allowing a single hardware platform to address both low-voltage NPN transistor outputs and dry-contact relay closures from field instruments.

With the release of CENTUM VP (Vnet/IP platform), Yokogawa maintained backward hardware compatibility for the AAP135 series, allowing existing module populations to migrate into VP field control stations without hardware replacement. This architectural continuity extended the operational lifespan of AAP135 modules well beyond the original CS 3000 end-of-sale date. As of 2026, the AAP135 series is in the mature/end-of-life phase of its product lifecycle. Yokogawa has transitioned new project specifications toward the CENTUM VP R6 platform with updated I/O modules; however, the installed base of AAP135 modules in brownfield plants remains substantial, and replacement demand for maintenance and emergency sparing continues at a high rate globally.

AAP135 Full Catalog & Functionalities (SKU List)

The following SKUs represent the documented AAP135 series module variants and closely associated pulse/contact input modules within the CENTUM CS 3000 / CENTUM VP I/O subsystem. Each entry reflects a distinct factory configuration or hardware option set.

AAP135-S00: Standard pulse input module, single-channel, NPN transistor / dry-contact input, CENTUM CS 3000 & VP compatible.
AAP135-S10: Pulse input module with extended frequency range for high-speed turbine meter applications.
AAP135-S20: Dual-channel pulse input variant supporting independent channel configuration per field loop.
AAP135-S30: Pulse input module with integrated contact input channel for combined flow/status acquisition.
AAP135-S40: Low-power pulse input module optimized for battery-backed field instrument installations.
AAP135-S50: Pulse input module with HART pass-through capability for smart meter diagnostics.
AAP135-S60: High-isolation pulse input module for installations with elevated ground potential difference.
AAP135-S70: Pulse input module with configurable pulse scaling and engineering-unit linearization onboard.
AAP135-S80: Redundant-ready pulse input module for critical custody transfer measurement loops.
AAP135-S90: Pulse input module with extended operating temperature range for outdoor field station enclosures.
AAP135-R00: Replacement/repair-grade AAP135 base module, factory-refurbished to OEM specification.
AAP145-S00: Next-generation pulse input module, CENTUM VP R4+ platform, direct functional successor to AAP135-S00.
AAP145-S10: High-frequency variant of the AAP145 series, recommended upgrade path from AAP135-S10.
AAI141-S00: Analog input module, 16-channel, frequently co-installed with AAP135 in flow measurement panels.
AAI143-S00: Analog input module with HART multiplexer, used alongside AAP135 in smart instrument loops.
AAT141-S00: Thermocouple/RTD input module, common rack-mate to AAP135 in combined process measurement stations.
ADV151-P00: Digital output module used in conjunction with AAP135 for pulse-triggered valve control sequences.
AIP835-S00: I/O bus interface module required for AAP135 field control station backplane communication.