The IS200DTAIH1A is a Simplex Analog Input/Output Terminal Board designed by General Electric (GE) for its Mark VI™ Control System. This board is the standard version within the DTAI series, featuring a compact design specifically for DIN-rail mounting. It provides analog signal acquisition and output functions for the control system. The IS200DTAIH1A board works in conjunction with the VAIC processor board, connecting via a single cable to process 10 analog inputs and 2 analog outputs.
The design of the IS200DTAIH1A board industrial field space limitations and application requirements. Its compact dimensions (8.6 cm wide × 16.2 cm high) allow multiple boards to be stacked vertically on a DIN rail, significantly saving control cabinet space. The board features permanently mounted high-density euro-block type terminal blocks with 48 terminals for connecting various field signals. An onboard ID chip identifies the board to the VAIC for system diagnostic purposes.
Key features of the IS200DTAIH1A include:
Compact Design: Suitable for DIN-rail mounting, can be stacked vertically to save cabinet space.
10 Analog Inputs: Supports 2-wire, 3-wire, 4-wire, and externally powered transmitters, as well as voltage inputs.
2 Analog Outputs: One fixed 0-20 mA output, and one configurable via jumper for 0-20 mA or 0-200 mA.
Coordination with VAIC: Connects to the VAIC processor board via a single cable. Each VAIC can support two DTAI boards, providing 20 inputs and 4 outputs total.
Configurable Input Types: Onboard jumpers allow inputs to be configured for current or voltage mode.
Transmitter Power Supply: Onboard 24 V dc power supplies all connected transmitters.
Noise Suppression: Features the same onboard noise suppression functionality as the TBAI.
ID Chip Identification: Onboard ID chip read by the VAIC ensures hardware compatibility.
The board operates within a temperature range of 0 to 60°C, suitable for industrial control cabinet environments. It is important to note that the DTAI is only available in a simplex version, does not support TMR applications, and has only one cable connection, so it cannot be used in TMR systems like the TBAI.
II. Main Functions
The primary functions of the IS200DTAIH1A include, but are not limited to, the following:
1. Analog Input Acquisition
The IS200DTAIH1A board provides 10 analog input channels that can interface with various types of signal sources:
2-Wire Transmitters: Supports common 4-20 mA two-wire transmitters.
3-Wire Transmitters: Supports three-wire transmitters requiring a separate power supply and common return.
4-Wire Transmitters: Supports independently powered four-wire transmitters.
Externally Powered Transmitters: Supports transmitters powered by an external source.
Voltage Inputs: Supports ±5 V dc or ±10 V dc voltage inputs.
Input signals are connected via the board's 48-terminal euro-block type terminal block. For current inputs, the maximum two-way cable resistance is 15 Ω, and cable length can be up to 300 meters (984 feet). Onboard 24 V dc power supplies all transmitters, providing 21 mA per connection point.
2. Analog Output Control
The IS200DTAIH1A board provides 2 analog output channels:
The maximum two-way cable resistance for output circuits is 15 Ω, with cable lengths up to 300 meters. For 4-20 mA outputs, the maximum load resistance is 500 Ω. For 200 mA outputs, the maximum load resistance is 50 Ω (when used with VAICH1C).
3. Coordination with VAIC
The IS200DTAIH1A connects to the VAIC processor board via a single 37-pin D-type connector with latching fasteners. Each VAIC can support two DTAI boards, providing a total of 20 analog inputs and 4 analog outputs. This configuration offers flexible I/O expansion capability for the control system.
4. Transmitter Power Supply
Onboard 24 V dc power supplies the connected transmitters. Each input channel connection point can provide up to 21 mA, ensuring normal transmitter operation. Power is sourced from the VAIC or an external supply.
5. Noise Suppression
The IS200DTAIH1A board features the same onboard noise suppression functionality as the TBAI, including hardware filtering and surge protection, ensuring signal accuracy and stability in industrial environments.
6. ID Chip Identification
The board features a read-only ID chip storing the board's serial number, type, revision number, and connector location information. The VAIC reads this information during initialization. If a mismatch is encountered, a hardware incompatibility fault is generated, preventing system problems caused by incorrect configuration.
7. Output Current Monitoring
The board indicates the output current value via the voltage drop across a series resistor. The I/O processor monitors both outputs and generates a diagnostic alarm if either output becomes unhealthy.
III. System Applications
1. Application in Mark VI Control System
The IS200DTAIH1A is a compact terminal board for analog I/O expansion within the Mark VI control system. Its roles within the system include:
Process Parameter Acquisition: Acquires analog signals from sensors measuring temperature, pressure, flow, level, etc., converting them via the VAIC to digital values for use by the controller.
Actuator Control: Outputs 4-20 mA or 0-200 mA signals to drive valve positioners, variable frequency drives, and other actuators.
Transmitter Power Supply: Provides 24 V operating power for 2-wire and 3-wire transmitters, simplifying field wiring.
I/O Expansion: Flexibly expands the system's analog I/O capacity by stacking multiple DTAI boards.
2. Differences from TBAI
The main differences between DTAI and TBAI are:
| Feature | DTAI | TBAI |
| Size | Compact (8.6 cm wide) | Standard (17.8 cm wide) |
| Mounting Method | DIN-rail | Panel mount |
| Channel Count | 10 inputs + 2 outputs | 10 inputs + 2 outputs (per board) |
| Connection Method | Single cable to VAIC | Two cables to VAIC (for TMR) |
| Redundancy Support | Simplex only | Supports Simplex and TMR |
| Stackability | Can be stacked vertically | Not stackable |
3. Typical Application Scenarios
Small Control Systems: Suitable for small control systems with limited I/O points and space.
Remote I/O Stations: Serves as an analog interface for remote I/O stations, communicating with the main controller via VAIC.
Process Control: Acquires various process parameters and outputs control signals to actuators.
Equipment Retrofits: Replaces larger traditional I/O modules in space-constrained legacy equipment upgrades.
IV. Detailed Interface Description
1. Terminal Block Signal Definitions
The 48-terminal euro-block type terminal block on the IS200DTAIH1A connects all input and output signals. Terminals 43 and 44 are dedicated for SCOM (shield common) connection and must be connected to chassis ground.
2. Connector
The board connects to the VAIC processor board via a single 37-pin D-type connector with latching fasteners. This cable is identical to those used on the larger TBAI terminal board, facilitating spare parts management.
3. Jumper Configuration
The IS200DTAIH1A uses multiple jumpers to configure input and output types:
| Jumper | Function | Setting Description |
| J1A-J8A | Inputs 1-8 Type Selection | Selects current input or voltage input |
| J1B-J8B | Inputs 1-8 Common Connection | Selects whether return is connected to common or left open |
| J9A-J10A | Inputs 9-10 Current Range Selection | Selects 1 mA or 20 mA input current |
| J9B-J10B | Inputs 9-10 Common Connection | Selects whether return is connected to common or left open |
| J0 | Output 2 Range Selection | Selects 20 mA or 200 mA output |
4. Grounding Requirements
Important: SCOM (terminal 43) must be connected to chassis ground to ensure shielding effectiveness and system stability. The board has no dedicated shield terminal strip, making this ground connection particularly critical.
V. Configuration and Installation
1. Installation Steps
Mount DIN Rail Holder: Install the plastic holder onto the DIN rail.
Install Board: Slide the DTAI board into the holder until it snaps into place.
Connect Wires: Connect transmitter and actuator wires directly to the terminal blocks. Use #18 AWG shielded twisted pair wiring.
Ground Connection: Connect terminal 43 (SCOM) to chassis ground using the shortest possible wire.
Connect Cable: Connect the 37-pin cable to the board and to the VAIC processor board.
Configure Jumpers: Set all onboard jumpers according to the actual signal types.
2. Jumper Setting Procedure
Determine the signal type (current/voltage, range) for each input channel.
For inputs 1-8, set J1A-J8A and J1B-J8B.
For inputs 9-10, set J9A-J10A and J9B-J10B.
Determine the range for output 2 and set J0.
Record the jumper settings for future maintenance.
3. Multi-Board Stacking
When multiple DTAI boards are required, they can be stacked vertically on the DIN rail. Each board connects independently to the VAIC (each VAIC can support up to two DTAI boards). When stacking, ensure adequate spacing between boards for heat dissipation and wiring access.
4. Wiring Precautions
Use shielded twisted pair wires to reduce electromagnetic interference.
Ensure the shield is grounded at a single point, either at the source or the destination.
The SCOM connection should be as short as possible and connected directly to chassis ground.
Transmitter wiring should follow the corresponding 2-wire, 3-wire, or 4-wire specifications.
VI. Diagnostics and Maintenance
1. Diagnostic Functions
The IS200DTAIH1A provides the following diagnostic functions:
| Diagnostic Item | Description |
| Output Current Monitoring | Monitors the voltage drop across a series resistor in the output circuit to determine if the output is normal. |
| ID Chip Verification | The VAIC reads the onboard ID chip and compares it with the configuration. A mismatch generates a hardware incompatibility fault. |
If either output channel becomes abnormal, the VAIC generates a diagnostic alarm. Users can view detailed fault information via the Toolbox software.
2. Common Troubleshooting
| Fault Symptom | Possible Cause | Troubleshooting Suggestions |
| Abnormal Input Signal | Incorrect jumper settings, transmitter fault, wiring error | Check jumper settings, test the transmitter, check wiring |
| No Output Signal | Incorrect jumper setting, open load, disconnected cable | Check J0 setting, check the load, check cable connection |
| Inaccurate Output Current | Excessive load resistance, excessive cable resistance | Check if load resistance is within allowable range, check cable length |
| Hardware Incompatibility Fault | ID chip information mismatch | Verify correct board model, contact GE technical support |
3. Maintenance Recommendations
Periodic Inspection: Check terminal blocks for looseness and wires for oxidation.
Cleaning: Regularly clean the board to prevent dust accumulation affecting heat dissipation and insulation.
ESD Protection: Wear a grounding strap when handling the board and store it in anti-static bags.
Spare Parts Management: Maintain a spare IS200DTAIH1A board to reduce downtime in case of failure.
