GE IS220PPDAH1A PPDA Power Distribution I/O Pack

The IS220PPDAH1A is a Power Diagnostic I/O Pack designed specifically for the Mark VIe and Mark VIeS control systems. It serves as the central feedback and monitoring unit for the Power Distribution Module (PDM), responsible for collecting, processing, and reporting the operational status of the entire power system. This module gathers critical information such as power bus voltages, branch circuit status, ground fault detection, and bulk power supply health.

Equipped with a BPPB processor board, the IS220PPDAH1A communicates via a dual-redundant Ethernet interface (IONet) to the controllers. While it has reached its end-of-life and is superseded by the IS220PPDAH1A (which features a BPPC processor), the IS220PPDAH1A remains a critical component in many existing installations, ensuring high reliability and real-time system monitoring.

2. Key Functions

• Power System Status Acquisition: The IS220PPDAH1A can receive feedback from up to six core power distribution boards (JPDx), monitoring:

• Power Bus Voltages: 28V DC control power, 125V DC battery power, 24/48V DC power, and 100-250V AC input power.

• Branch Circuit Status: Fuse status, switch position, and output circuit validity.

• Ground Fault Detection: Detects faults in floating DC systems by monitoring voltage offset from earth.

• Bulk Power Supply Health: Reads dry contact status signals from external power supplies.

• Electronic Identification & Auto-Configuration: The module uses electronic ID lines to automatically identify the type and revision of each connected JPDx board. This "plug-and-play" capability allows the PPDA to

• populate the IONet signal space correctly without manual reconfiguration.

• Dual-Redundant Ethernet Communication: Two Ethernet ports provide redundant communication paths to the R, S, and T controller networks, ensuring continuous data reporting even if one network link fails.

• Status Indication via LEDs: The front panel features 24 LEDs that provide an immediate visual summary of the power system's health, including power bus regulation, source status, battery voltage/grounding, and user-configurable alarm points.

• Comprehensive Diagnostics: The IS220PPDAH1A performs extensive self-diagnostics, including power-up self-tests (RAM, Flash, Ethernet, processor hardware), continuous internal power supply monitoring, and analog input circuit validation. All diagnostic signals are accessible and manageable via the ToolboxST application.

3. Operational Principle

• Signal Input & Processing: The IS220PPDAH1A connects to a host board (JPDS, JPDM, JPDG, or JPDC) via a 62-pin connector. Each connected JPDx board provides one "feedback group" consisting of a feedback ground, five analog signals, and an ID line. The PPDA reads analog signals differentially to ensure high immunity to common-mode noise.

• Electronic ID Mechanism: The ID line in each feedback group allows the PPDA to identify the board type. Based on this identification, the IS220PPDAH1A applies the correct signal interpretation logic, enabling automatic integration.

• Analog Signal Conversion & Alarm Generation: A 16-bit analog-to-digital converter samples the input signals. The IS220PPDAH1A firmware compares these values against user-configurable thresholds (e.g., voltage tolerances, ground fault triggers) to generate alarms reported to the controller via IONet.

• Feedback Daisy-Chain: The IS220PPDAH1A must be hosted on a main board and must be the terminal point of the diagnostic daisy-chain. Other core boards are connected in series using 50-pin ribbon cables from their P2 connector to the next board's P2 connector, culminating at the IS220PPDAH1A host.

4. Installation & Configuration

• Installation Steps:

1. Securely mount the host terminal board (e.g., JPDS, JPDC).

2. Directly plug the IS220PPDAH1A I/O pack into the host board's JA1 connector.

3. Mechanically secure the I/O pack using the threaded studs and a mounting bracket to prevent strain on the connector.

4. Connect one or two Ethernet cables (ENET1 typically to the R controller network).

5. Connect the power cable; the pack supports hot-plugging with soft-start capability.

6. Use ribbon cables to daisy-chain other core boards from their P2 connector to the host board's P2 connector.

• ToolboxST Configuration: Key configuration parameters include PS28vEnable (28V feedback enable), InputDiagEnab (input diagnostic enable), DC_125v_Trig_Volt (125V DC fault trigger voltage), Gnd_Mag_Trig_Volt (ground fault trigger voltage), and FuseDiag (fuse diagnostic enable).