IS220PDIOH1A, REV E - Discrete Contact Input/Output Terminal Board

SPECIFICATIONS:

Part Number: IS220PDIOH1A, REV E
Manufacturer: General Electric
Series: Mark VIe
Product Type: Discrete Contact Input/Output Terminal Board
Number of input channels: 24
Input Filter: Hardware filter, 4 ms
Input Signal Logic: Active High / Active Low
Input isolation in pack: 1500 V
Input Voltage Range: 5V DC / 24V DC
Ac voltage rejection: 60 V RMS
Isolation: Optical or Galvanic Isolation
Output Voltage Range: 5V DC – 250V AC
Contact Rating (Relay Output): 5A
Response Time: <5ms
Number of relay command channels: 12
Number of input channels: 24 DI and 12 form C
Operating Temperature: -40°C to +70°C
Mounting Type: DIN Rail
Size: 15.875 cm high x 10.795 cm wide
Country of Origin: United States
Availability: In Stock
Manual: GEH-6721G

FUNCTIONAL DESCRIPTION:

IS220PDIOH1A, REV E is a Discrete Input/Output Module Manufactured and Designed by General Electric as Part of the Mark VIe Series used in Distributed Control Systems. The Discrete Input/Output (PDIO) pack serves as the electrical interface between one or two I/O Ethernet networks and a discrete input/output terminal board. It features a processor board common to all Mark VIe distributed I/O packs and an acquisition board specific to discrete I/O functions. The pack supports up to 24 contact inputs, 12 relay outputs, and terminal board-specific feedback signals.

The terminal board determines the voltage capability of the PDIO. System input is provided via dual RJ45 Ethernet connectors and a three-pin power input, while discrete signal I/O is managed through a DC-62 connector linking directly to the terminal board. Indicator LEDs enable visual diagnostics, and an infrared port allows for local serial communication.
Functionally, the PDIO combines the capabilities of a PDIA and PDOA I/O pack into a single unit. In simplex applications, it is used with a TDBS terminal board, integrating the functions of an SRLY relay terminal board and an STCI contact input terminal board. For TMR applications, it connects to a TDBT terminal board, which, with the WROB option, provides the functionality of a TRLYH1B relay terminal board and a TBCI contact input terminal board.

INSTALLATION:

For simplex applications, a single PDIO I/O pack is plugged directly into the terminal board connector, while TMR applications require three PDIO I/O packs. The packs are mechanically secured using threaded studs near the Ethernet ports, which slide into a mounting bracket designed for the terminal board type. This bracket should be adjusted once during installation to prevent any right-angle force on the DC-62 pin connector. Depending on the system configuration, one or two Ethernet cables can be connected, with ENET1 typically linked to the network associated with the R controller. Power is applied by plugging in the side connector, and the pack’s soft-start capability manages the current inrush, eliminating the need to disconnect power before insertion.

OPERATION:

The processor board connects to an acquisition board tailored to the I/O pack function. When power is applied, a soft-start circuit gradually increases the voltage to the processor board, initiating a sequenced startup of local power supplies and removing the processor reset. The processor then conducts self-tests and loads application code from flash memory, ensuring compatibility with the acquisition board and terminal board through board ID verification. If the components match, the processor begins Ethernet communication by requesting a network address using DHCP and the terminal board’s unique identification. Once Ethernet is initialized, the processor configures onboard logic, runs the application, and activates the acquisition board.

The application code enables operation with one or two Ethernet inputs, keeping both network paths active simultaneously. If one network fails, the I/O pack continues functioning without disruption, with the failure reported through the operational connection. This approach enhances fault tolerance compared to a hot-backup system, where a secondary connection activates only after detecting a primary failure. The Ethernet ports support auto-negotiation between 10 MB/s and 100 MB/s, as well as half-duplex and full-duplex modes. The processor board in the pack is common to all Mark VIe Ethernet I/O packs. It contains the following:

• High-speed processor with RAM and flash memory
• Two fully independent 10/100 Ethernet ports with connectors
• Hardware watchdog timer and reset circuit
• Internal I/O pack temperature sensor
• Infrared serial communications port
• Status-indication LEDs
• Electronic ID and the ability to read IDs on other boards
• Substantial programmable logic supporting the acquisition board
• Input power connector with soft start/current limiter
• Local power supplies, including sequencing and monitoring

RELAY COMMAND SIGNALS:

The PDIO relay command signals serve as the initial stage for signal conditioning and level shifting, linking terminal board outputs to the control logic. Each output uses an open collector transistor circuit with a current monitor to detect when it is engaged and connected to a load. Status LEDs and monitor outputs indicate the engagement status. If an output is activated but the expected load is not detected, the status LED remains off, and the monitor line stays false. The LEDs are positioned at the top left of the PDIO pack.

WOC has the largest stock of OEM Replacement Parts for GE Distributed Turbine Control Systems. We can also repair your faulty boards and supply unused and rebuilt boards backed up with a warranty. Our team of experts is available round the clock to support your OEM needs. Our team of experts at WOC is happy to assist you with any of your automation requirements. For pricing and availability on parts and repairs, kindly contact our team by phone or email.

FREQUENTLY ASKED QUESTIONS:

What is a Discrete Contact Input/Output Terminal Board?

A Discrete Contact Input/Output (I/O) Terminal Board is a hardware component used in industrial control systems to interface discrete signals with control processors. It provides connection points for contact inputs and relay outputs, enabling communication between field devices and the control system.

What types of signals are handled by the terminal board?

The terminal board manages discrete (binary) signals, typically represented as ON/OFF states. It processes contact inputs, which detect open or closed circuits, and relay outputs, which switch external loads on or off. The board is designed to work with different voltage levels depending on system requirements and terminal board specifications.

How is the terminal board connected to the control system?

The board connects to the control system via a high-density connector, such as a DC-62 or similar interface, ensuring a secure and stable connection. Communication with the control processor is typically established through Ethernet or dedicated backplane connections, depending on the system architecture. Proper mounting and securing of connectors prevent signal integrity issues.