GE IS220PDOAH1A PDOA Discrete Output Pack

The IS220PDOAH1A is a Discrete Output I/O module used in GE's Mark VIe and Mark VIeS Control Systems, representing a specific hardware version within the PDOA series. This module is primarily used in industrial automation and control systems to enable remote control and status monitoring of relay devices. The IS220PDOAH1A module incorporates a BPPB processor board, providing robust signal processing and communication capabilities, making it suitable for high-reliability industrial applications such as gas turbines, steam turbines, wind power generation, and process control.

The module connects to the control system network (IONet) via dual Ethernet interfaces, supporting redundant network communication to ensure high data availability. Its output channels can control up to 12 relays and include comprehensive functions such as relay driving, status feedback, fuse monitoring, and self-diagnostics, meeting the configuration requirements for both Simplex and TMR (Triple Modular Redundant) systems.

2. Hardware Structure and Interfaces

2.1 Module Composition

The IS220PDOAH1A module consists of two core printed circuit boards:

• BPPB Processor Board: Responsible for communication protocol handling, logic control, self-diagnostics, and data reporting.

• Acquisition Board: Dedicated to driving discrete output signals and acquiring feedback, providing functions like level shifting, current monitoring, and relay driving.

2.2 External Interfaces

• DC-37 Pin Connector: Located on the underside of the module, used for direct connection to relay terminal boards (e.g., TRLY series).

• Dual RJ-45 Ethernet Ports (ENET1, ENET2): Support redundant network connections. ENET1 is typically connected to the primary controller network.

• 3-pin External Power Input: Accepts 28 V DC power to supply the module and the terminal board.

2.3 Mechanical Structure

• Dimensions: 8.26 cm (H) × 4.19 cm (W) × 12.1 cm (D)

• Mounting Method: Plugs directly into the terminal board and is secured using threaded studs to prevent side-force on the connector.

3. Functions and Operating Principles

3.1 Relay Command Signal Output

The IS220PDOAH1A receives command signals via Ethernet from the controller and outputs relay drive signals through its internal acquisition board. Each output channel uses an open-collector transistor circuit with current monitoring capability to detect whether the relay has picked up correctly and is connected to a load. When an output is activated:

• The corresponding yellow status indicator (LEDs 1–12) illuminates.

• The current monitor circuit detects load current, and the feedback signal becomes TRUE.

• If no current is detected, the indicator remains off, the feedback is FALSE, and the system can identify an output fault.

3.2 Output Enable Control

During initial power-up, all outputs are automatically disabled until the following self-tests are completed:

• RAM and Flash memory checks

• Ethernet port detection

• Processor hardware self-test

• Power supply monitoring

An Enable Line activates the outputs only after all conditions are met, ensuring relays remain de-energized during system initialization to prevent misoperation.

3.3 Monitor Inputs and Feedback Processing

The IS220PDOAH1A features 15 inverting level-shifting monitor input circuits used to acquire the following feedback signals:

• 12 Relay Contact Feedback channels

• 3 Fuse Status Feedback channels

Additionally, the module supports feedback multiplexing control, allowing it to read two sets of 15 signals from the terminal board via a control line for comprehensive monitoring of complex terminal board states.

3.4 Sequence of Events (SOE) Recording

Each relay channel can be configured to generate an SOE record upon a state change, used for fault analysis and system behavior tracing. It is recommended to prioritize using relay feedback signals (rather than output commands) as the SOE source for improved accuracy.

3.5 Power Load Unbalance (PLU) Function

This function is specific to GE industrial applications and requires coordination with a PGEN module to monitor power load status and prevent system faults caused by load imbalance. Detailed descriptions can be found in the GEH-6721_Vol_III manual.

4. Compatibility and System Configuration

4.1 Compatible Terminal Boards

The IS220PDOAH1A supports various relay output terminal boards, including:

Note: Simplex systems use 1 PDOA module; TMR systems use 3 modules.

4.2 Software and Firmware Requirements

• Supports the ControlST software suite V04.04 and later

• Configuration, parameter setting, and diagnostics can be performed using the ToolboxST application

5. Installation and Wiring

Installation Steps:

1. Mount the Terminal Board: Securely install the selected relay terminal board.

2. Plug in the PDOA Module: Insert the module directly into the terminal board's DC-37 connector.

3. Mechanically Secure: Use the threaded studs adjacent to the Ethernet ports to secure the module to the mounting bracket.

4. Connect Network:

• Simplex: Connect one or two Ethernet cables.

• TMR: Connect one cable per module; typically connect ENET1 to the R controller network.

5. Apply Power: Plug in the 28 V DC power connector. The module has soft-start capability, so power does not need to be removed before connection.

6. Software Configuration: Use ToolboxST to configure module parameters such as relay enable, SOE recording, and fuse diagnostics.

6. Diagnostics and Status Indication

6.1 Self-Diagnostic Functions

The IS220PDOAH1A continuously performs the following self-checks during operation:

• Power supply monitoring

• Processor and memory checks

• Ethernet communication status

• Comparison between relay command and feedback states

• Verification of terminal board electronic ID

• Fuse status reading

6.2 Status Indicators

• Yellow LEDs 1–12: Indicate whether each relay output is commanded to energize.

• Processor LEDs: Display module communication, power, fault, and other statuses (refer to Common Module documentation).

6.3 Common Alarms and Handling