ALSTOM AS111-1 Analog Output (AO) Module

Introduction to ALSTOM AS111-1

The ALSTOM AS111-1 is a high-precision Analog Output Module designed for industrial control and automation systems.

It functions as a critical bridge between a digital control environment (such as a DCS or PLC) and analog-driven field devices.

By converting 16-bit digital signals into standardized analog currents or voltages, the AS111-1 allows for the fine-tuned control of valves, actuators, and motor speed controllers.

Often integrated into Alstom’s legacy power and rail control platforms (now frequently supported under GE or specialized industrial automation vendors), the AS111-1 is prized for its high resolution and reliability in electrically noisy environments.

Technical Parameter Table

Related Models & Same Series

The AS111 series is part of a modular I/O family:

AS111-2: An upgraded or dual-channel variant often featuring different output impedances or safety certifications (ATEX/IECEx).

AS1111A/B/C: (Note: Sometimes cross-referenced) Small-scale LED driver versions used in specific signaling backlights.

PIB-101C / PIB-201A: Companion power and interface boards used in the same rack architecture.

UT150-1: A common control card often found in the same power system cabinets as the AS111 series.

Product Advantages and Features

High Resolution: The 16-bit digital-to-analog conversion ensures extremely smooth control curves, vital for sensitive chemical processes or high-speed rail braking.

Wide Temperature Range: Unlike standard commercial electronics, the AS111-1 operates reliably from -40°C up to +85°C, making it suitable for unconditioned outdoor cabinets.

Ruggedized Protection: Many versions carry an IP66 rating, providing superior protection against dust and moisture ingress.

Programmable Logic: Supports customization of output behavior (e.g., “fail-safe” states where the output drops to a specific value if communication is lost).

Isolation: High galvanic isolation between the digital backplane and the analog field circuits to prevent ground loops.

Application Cases

Rail Transit Signaling: Managing the variable voltage required for signaling lamps and trackside automation units.

Power Plant Control: Regulating steam valves or fuel flow in turbine control systems where precision is synonymous with efficiency.

Wastewater Treatment: Controlling variable frequency drives (VFDs) for high-capacity pumps based on real-time flow sensors.

Environmental Monitoring: Interfacing with analog recorders to track temperature, humidity, and gas concentrations in industrial zones.

Installation and Maintenance

Installation

Backplane Mounting: The module should be firmly seated in its designated slot. Ensure the locking mechanisms are engaged to prevent “creep” under vibration.

Shielding: For 4-20mA loops, use shielded twisted-pair cabling. Connect the shield to a single point (usually at the cabinet ground) to minimize EMI.

Calibration: While factory-calibrated, it is recommended to verify the 4mA and 20mA setpoints using a precision multimeter during commissioning.

Maintenance

Diagnostic Check: Utilize the system’s SCADA interface to check for “Output Open Circuit” or “Loop Power Failure” alarms.

Cleaning: During scheduled outages, use dry air to remove dust from the module’s heat sinks to maintain its wide-temperature performance.

Terminal Tightening: In high-vibration environments (like rail), check that the field wiring terminals remain tight to avoid intermittent signal loss.

Unique Product Description

The ALSTOM AS111-1 is the “translator” of the industrial world. In a system where the “brain” thinks in binary ones and zeros, the AS111-1 speaks the fluid, variable language of the physical world.

It is a rare combination of extreme sensitivity (0.1% accuracy) and rugged durability (IP66 and -40°C rating).

Whether it is ensuring a train stops exactly at the platform or maintaining the precise pressure in a boiler, the AS111-1 provides the reliable, steady hand that industrial processes demand.