Description
GE IS220PDIOH1A | Mark VIe PDIO Discrete I/O Pack | 24 DI / 12 Relay Outputs
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | IS220PDIOH1A |
| Manufacturer | General Electric |
| Product Family | Mark VIe Distributed I/O |
| Functional Abbreviation | PDIO |
| Product Type | Discrete Input/Output I/O Pack |
| Contact Inputs | Up to 24 |
| Relay Output Channels | Up to 12 |
| Ethernet Interfaces | 2 × Ethernet IONet |
| Power Supply | 28.0 VDC nominal |
| Supply Range | 27.4–28.6 VDC |
| Maximum Pack Current | 0.81 A DC |
| Contact Input Voltage | 0–32 VDC maximum |
| Contact Output Voltage | Up to 32 VDC |
| Maximum Contact Output Current | 3.15 A |
| Input Isolation | Optical isolation; 1500 V documented |
| Input Filter | 4 ms hardware filter |
| Terminal Board | IS200TDBSH2A / IS200TDBTH2A |
| Field Interface | DC-62 terminal-board connection |
| Application | Mark VIe turbine control |
GE’s GEH-6725R documentation gives the H1A PDIO pack a 28.0 VDC nominal supply, 0.81 A maximum supply current, 0–32 VDC contact-input range, and up to 3.15 A for contact outputs. It also distinguishes contact-wetting output ratings from relay-contact output ratings, so generic “24 V / 2 A digital I/O” descriptions should not be used as the primary specification.
Product Introduction
The GE IS220PDIOH1A is a Mark VIe PDIO Discrete Input/Output I/O Pack. It provides the electronics between one or two Mark VIe I/O Ethernet networks and a compatible discrete terminal board, combining the acquisition and processing functions required for contact inputs and relay outputs in one I/O-pack architecture.
The pack can accept up to 24 contact inputs and manage up to 12 relay outputs. Its field voltage capability is determined by the terminal-board configuration, which is why the IS220PDIOH1A should always be purchased together with verification of the installed TDBS/TDBT terminal board, rather than treating the pack as a standalone universal 24 VDC I/O module.
IS220PDIOH1A
Application Scenarios & Field Pitfalls — Engineer’s Perspective
Engineering Pain Point
The common mistake with IS220PDIOH1A is to identify it only as a “24-channel digital input module.” That description misses the relay-output function and, more importantly, ignores the terminal board that determines the actual field interface.
Typical Applications
- GE Mark VIe Turbine Control — discrete field signal acquisition and relay command output.
- Gas and Steam Turbine Auxiliary Systems — contact monitoring and discrete actuator commands.
- Simplex PDIO Applications — one PDIO pack connected to a TDBS terminal board.
- TMR PDIO Applications — three PDIO packs connected through a TDBT terminal-board arrangement. GE documentation identifies TDBSH2/TDBSH4/TDBSH6 for simplex configurations and TDBTH2/TDBTH4/TDBTH6 for TMR configurations.
Technical Pitfalls to Avoid
- Match the terminal board, not just the I/O pack.
The H1A pack is documented with IS200TDBSH2A and IS200TDBTH2A for the applicable hazardous-location configuration. Later H1B hardware supports additional TDBS/TDBT variants, so an H1B should not automatically be assumed to be a direct H1A substitute. - Do not use reseller channel counts from unrelated Mark VIe modules.
Several listings incorrectly describe this unit as 16 DI/16 DO or add analog I/O specifications. GE’s PDIO documentation instead describes up to 24 contact inputs and 12 relay outputs. - Check whether the application is simplex or TMR.
Simplex uses one I/O pack with one or two network connections. TMR uses three I/O packs, with one network connection per pack. The terminal-board configuration must match that architecture. - Verify the field voltage from the terminal board.
The PDIO pack’s field voltage capability is not a universal “24 VDC output” specification. GE documentation lists different TDBS/TDBT versions for 24, 48, and 125 VDC applications. - Do not confuse PDIO with PDIA or PDOA.
PDIA is the Mark VIe discrete-input pack, while PDOA is the discrete-output pack. PDIO combines the discrete input/output function into one pack architecture.
Related Products
- IS220PDIAH1A — Mark VIe discrete input I/O pack; input-only architecture.
- IS220PDOAH1A — Mark VIe discrete output I/O pack; output-oriented architecture.
- IS200TDBSH2A — simplex PDIO contact-input/relay-output terminal board.
- IS200TDBTH2A — TMR PDIO terminal-board configuration.
- IS200TDBSH4A — 48 VDC simplex terminal-board variant.
- IS200TDBSH6A — 125 VDC simplex terminal-board variant.
- IS200TDBTH4A — 48 VDC TMR terminal-board variant.
- IS200TDBTH6A — 125 VDC TMR terminal-board variant.
- IS220PDIOH1B — later PDIO hardware revision supporting a broader set of terminal-board combinations.
Procurement Note
For GE IS220PDIOH1A, the minimum procurement specification should include:
- Complete part number:
- Hardware/revision identification
- Installed TDBS or TDBT terminal board
- Simplex or TMR architecture
- Field voltage: 24, 48, or 125 VDC as applicable
- Number and type of contact inputs
- Relay-output configuration
- IONet topology
- Existing Mark VIe control software and configuration
One particularly important distinction is that is an I/O Pack, not the terminal board itself. The pack communicates with the field through its associated terminal board, and the terminal-board selection determines important field-interface characteristics.
For a replacement, I would verify the IS200TDBS/TDBT board number and its suffix before approving the purchase. That check is more valuable than relying on a generic supplier specification sheet for .
