Description
GE IS200DTAOH1ABA | Mark VI DTAO Analog Output Terminal Board
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | GE |
| Board Number | IS200DTAOH1ABA |
| Functional Designation | DTAO |
| Platform | GE Mark VI Turbine Control |
| Product Type | Simplex Analog Output Terminal Board |
| Number of Outputs | 8 |
| Output Type | Analog current |
| Output Range | 0–20 mA |
| Typical Control Range | 4–20 mA |
| Maximum Load | 500 Ω |
| I/O Processor | VAOC |
| VAOC Connection | 37-pin D-type connector |
| Field Terminal Block | 36-position Euro-block |
| Mounting | DIN rail |
| Typical Field Wiring | #18 AWG shielded twisted pair |
| Maximum Field Cable Distance | 300 m / 984 ft |
| Ground Connection | SCOM / chassis ground |
| Operating Temperature | 0 to 60°C |
| System Architecture | Simplex only |
GE’s Mark VI documentation identifies DTAO as a compact analog-output terminal board with eight current-output channels, driven by the VAOC I/O board. The documentation specifies 0–20 mA outputs, loads up to 500 Ω, and a 37-pin connection between DTAO and the VAOC rack.
Product Introduction
The GE IS200DTAOH1ABA is a DTAO terminal board used in the GE Mark VI turbine control system. It provides the physical field-wiring interface for eight simplex analog control outputs generated by the VAOC analog-output board. The board is mounted on a DIN rail and connects to the VAOC through a single 37-pin D-type cable.
The DTAO does not perform the digital-to-analog conversion itself. The VAOC contains the D/A converter and output drivers, while the DTAO provides current-loop termination, current feedback, filtering, surge suppression, and field wiring. This distinction matters when diagnosing an output failure because a bad signal can originate in the VAOC, interconnecting cable, DTAO circuitry, or field device.
IS200DTAOH1ABA
Application Scenarios & Field Pitfalls — Engineer’s Perspective
Engineering Pain Point
A failed IS200DTAOH1ABA can appear to be a VAOC failure because the terminal board is directly involved in the analog current loop. If several outputs are affected simultaneously, check the VAOC, 37-pin cable, DTAO board, and common grounding before replacing individual field devices.
Typical Applications
- GE Mark VI gas and steam turbine control systems
- Governor and actuator control loops
- Valve-position and process-control outputs
- Simplex analog control circuits requiring 4–20 mA signaling
Technical Pitfalls to Avoid
- Do not confuse DTAO with TBAO.
DTAO is the compact eight-channel simplex terminal board. TBAO is a larger terminal-board architecture supporting up to 16 analog outputs and different system configurations. - Do not pair it with a PAOC/PAOCH1A I/O pack.
GE documentation specifically states that the DTAO board is designed for the VAOC and does not work with the PAOC I/O pack. This is one of the most important compatibility checks when replacing an older Mark VI board. - Check the output load.
GE specifies a maximum driven-device resistance of 500 Ω for the DTAO output circuit. Excessive loop resistance can produce current-output errors that may initially look like a defective terminal board. - Inspect the 37-pin cable and connector.
The DTAO depends on its single D-type connection to the VAOC. Loose locking hardware, damaged pins, cable faults, or contamination can affect multiple channels simultaneously. - Check SCOM grounding.
GE provides dedicated SCOM/chassis-ground connections on the DTAO and recommends keeping the ground connection short. Poor grounding can increase noise or create misleading analog-output diagnostics.
Related Products
- GE VAOC — Mark VI VME analog-output board that generates and controls the DTAO current outputs.
- GE IS200DTAOH1A — DTAO board designation associated with the simplex eight-channel analog-output terminal architecture; verify the complete suffix before substitution.
- GE TBAO — Larger Mark VI/Mark VIe analog-output terminal-board architecture supporting up to 16 analog outputs.
- GE IS220PAOCH1A — Mark VIe PAOC analog-output I/O pack; not compatible with DTAO according to GE documentation.
- GE TBAOH1C — Mark VIe-compatible TBAO analog-output terminal board for PAOC applications.
- GE VAIC — Mark VI analog I/O board used in other analog input/output configurations.
- GE IS200DTAIH1ABB — Related Mark VI DTAI simplex analog input/output terminal-board family; functionally different from DTAO.
- GE Mark VI VME I/O rack — Hosts the VAOC and associated Mark VI control electronics.
Procurement Check
Before approving an IS200DTAOH1ABA replacement, verify:
- Exact board marking: IS200DTAOH1ABA
- Mark VI rather than Mark VIe architecture
- DTAO functional designation
- VAOC I/O board installed in the host system
- 37-pin JR1 connector and cable
- Eight-channel requirement
- Field output range and loop load
- DTAO terminal-block condition
- SCOM/chassis-ground arrangement
- DIN-rail mounting hardware
- Board revision and PCB artwork
- Existing Mark VI application configuration
Recommended procurement description:
GE DTAO Simplex Analog Output Terminal Board, Mark VI Turbine Control, 8-Channel 0–20 mA Analog Output Interface, VAOC Compatible, 37-Pin D-Type Connection, DIN-Rail Mount.
The key replacement point is that is a Mark VI DTAO terminal board, not a standalone analog-output processor. The VAOC performs the D/A conversion and output driving; the DTAO handles the field termination and signal-conditioning interface. Most importantly, verify the installed VAOC architecture before substituting any Mark VIe PAOC hardware.
