Product Description

The AAI841-S50 is a high-density analog input module designed for the Yokogawa CENTUM VP control system. This variant is specifically engineered for harsh industrial environments, as indicated by the S50 suffix, which denotes a G3 conformal coating. This protective coating safeguards internal circuitry against corrosive gases, moisture, and airborne contaminants, making the module well-suited for wastewater treatment plants, chemical processing facilities, and coastal or offshore installations.

The module supports 16 analog input channels, typically connected to 4–20 mA field transmitters. It provides galvanic isolation between field wiring and the system bus, minimizing the risk of ground loops and protecting the Field Control Station (FCS) from electrical disturbances. With a fast update cycle, the AAI841-S50 ensures timely delivery of process data for accurate PID control and safety monitoring.

Technical Specifications

Functional Comparison: S50 vs. S00 Variants

The key difference between the AAI841-S50 and the standard S00 variant lies in environmental protection:

• S00: Intended for clean, climate-controlled control rooms

• S50: Qualified for ISA-S71.04 Class G3 environments, including exposure to corrosive gases such as Hydrogen Sulfide (H₂S), Chlorine (Cl₂), and Sulfur Dioxide (SO₂)

This makes the S50 version the preferred option for aggressive or contaminated industrial atmospheres.

Frequently Asked Questions

Q: Does the AAI841-S50 support redundant operation?
A: Yes. When installed on a redundancy-capable baseplate, the module can be deployed in pairs to support high-availability (up to 99.9999%) system configurations.

Q: Is the AAI841-S50 compatible with older CENTUM CS 3000 systems?
A: Yes. The AAI841 series is compatible with CENTUM VP and CENTUM CS 3000 R3, provided the correct FIO nodes and baseplates are used.