GE IS200VAICH1C Mark VI Analog I/O Board | 24-Channel VAIC Processor

Product Overview

The GE IS200VAICH1C is a VME Analog Input/Output (VAIC) board for the Mark VI turbine control system. This versatile board supports both TMR (triple modular redundant) and Simplex configurations for gas and steam turbines. It accepts 20 analog inputs and controls 4 analog outputs, making it essential for turbine monitoring and control applications.

Core Functionality

The VAIC board converts analog field signals to digital values for transmission over the VME backplane to the VCMI board and controller. For outputs, it converts digital values to analog currents (4-20mA or 0-200mA) and drives them to field devices. In TMR configurations, input signals fan out to three racks (R, S, T) with automatic median voting on outputs. If one VAIC fails, it is removed from the output circuit while the remaining two maintain correct current output. The board also executes gas turbine compressor stall detection at 200Hz using pressure transducer inputs.

Technical Specifications

Compatibility

The IS200VAICH1C belongs to the original VAIC generation (versions up to and including VAICH1C). For proper operation, use terminal board TBAIH1B or earlier, or any revision of DTAI. This generation supports up to 500Ω load resistance at 20mA output with 1000ft of #18 wire. For newer VAICH1D and subsequent releases requiring higher load resistance (up to 800Ω), use TBAIH1C or later, or any STAI revision. Note that VAICH1C is not compatible with newer terminal board generations.

Installation Guide

Power down the VME processor rack before installation. Slide the IS200VAICH1C into the rack slot, then push the top and bottom levers simultaneously to seat the edge connectors fully. Tighten the captive screws at the top and bottom of the front panel. Connect the terminal board cables to the rear connectors. For TMR systems, ensure all three VAIC boards (R, S, T) are installed with matching firmware revisions. Verify the terminal board ID chip is read correctly during power-up.

Engineering Advantages

The IS200VAICH1C provides 24 channels of analog I/O with support for both TMR and Simplex architectures. The median voting scheme on TMR outputs ensures continued operation through single-channel failures. Built-in compressor stall detection at 200Hz enables rapid turbine protection response. Diagnostic features include hardware limit checking, configurable system limits, TMR signal deviation detection, and ID chip verification. The conformal coating protects against moisture and contamination in harsh turbine environments. LEDs provide immediate visual status (flashing green for RUN, solid red for FAIL, steady orange for diagnostic alarm). At approximately 0.5 kg (1.1 lbs), the board is lightweight for easy handling during installation.

Technical FAQs

Q1: Difference between VAICH1C and VAICH1D?
A1: VAICH1C supports 500Ω load at 20mA. VAICH1D supports 800Ω with 18V at terminals. VAICH1C requires TBAIH1B or earlier.

Q2: Can this board work in Simplex mode?
A2: Yes. The IS200VAICH1C supports both Simplex and TMR configurations with full functionality.

Q3: What does compressor stall detection do?
A3: Executes at 200Hz using pressure transducers. Trip signal initiates fuel shut-off valve closure for turbine protection.