Yokogawa AAI841-S00 S2 Analog I/O Module

Configured for simultaneous field sensing and control execution in CENTUM VP and CENTUM CS 3000 systems, the Yokogawa AAI841-S00 S2 (AAI841 Analog Input/Output Module) provides direct physical/electrical execution.

Hardware Specifications

Process Control Integration & Fieldbus Management

The AAI841-S00 S2 functions within the standard Field I/O (FIO) architecture to manage continuous loop processes. The subsystem implements specific signal parameters:

• Loop Protocol Processing: The hardware processes standard 4 to 20 mA analog feedback loops. This variant is a non-HART analog module, establishing direct and unmodulated DC path representations of process variables.
• Channel-to-Channel Isolation: This module operates on a non-isolated common-ground design. Ground potential differences must be minimized across all field devices to avoid measurement offsets.
• Transmitter Power Supply: Built-in power generation delivers 14.8 V DC or higher (at 20 mA load) to power standard 2-wire transmitter circuits directly from the input terminal connections.

Frequently Asked Questions

Q: Does the AAI841-S00 S2 support dual-redundant configurations?

A: Yes. The module can be installed in pairs within a redundant FIO terminal sub-unit. In this layout, the secondary module remains in a hot-standby state, ready to assume control without process bump if a hardware failure is detected on the primary module.

Q: What is the significance of the "S00" and "S2" designators?

A: The "S00" suffix represents the standard non-HART communications hardware with basic non-explosion protection. The "S2" designator refers to the physical style and component revision of the module's enclosure and integrated circuit assembly.

Q: How does the module handle open-circuit detection on its inputs?

A: The module incorporates an integrated diagnostic routine that triggers a circuit-open alarm when the measured current on any active input channel falls below 0.65 mA.

Field Installation Guidelines

• ESD Mitigation Protocol: Grounding wrist straps must be used when removing or inserting modules to prevent static discharge to exposed backplane connectors.
• Common-Ground Wiring Precautions: Because the analog channels are non-isolated, ensure that all connected field transmitters share a stable, equipotential ground plane. Significant ground loop currents will corrupt analog measurement accuracy and can damage the module's multiplexer circuitry.
• Interface Cable Connection: Field connections can be established using a standard ATA4S pressure clamp terminal block, or via KS cables routed to dedicated external interface panels. Connectors must be locked into place using the integrated retaining screws.
• Chassis Slot Alignment: Align the plastic guide keys of the module with the targeted slot in the FIO node. Slide the module straight into the slot until the latching mechanism clicks to confirm secure connection with the backplane.