GE IS220YDOAS1AK Modules

Technical Dossier

Product Details And Specifications

GE IS220 Series Technical Notes

The GE IS220 series represents the I/O and control module family deployed within GE's Mark VIe turbine control platform — one of the most widely installed DCS architectures in heavy industry globally. Mark VIe systems are found in gas turbine power plants, combined-cycle facilities, nuclear auxiliary systems, LNG terminals, and petrochemical complexes across North America, the Middle East, and Asia-Pacific. The IS220 module family forms the backbone of the Mark VIe I/O subsystem, handling analog input, digital output, analog output, servo control, and communication functions across the turbine control rack.

DriveKNMS reviews sourcing options for this model through RFQ handling before quotation.

The Evolution of IS220 Architecture

The IS220 module family was introduced alongside the Mark VIe platform in the early 2000s as GE's successor to the Mark V and Mark VI turbine control systems. The Mark V used the IS200 series I/O boards with a VME-based backplane; the transition to Mark VIe brought a new IONet Ethernet-based I/O communication architecture, replacing the older serial I/O bus with a deterministic 100 Mbps Ethernet backbone.

The IS220 modules communicate over this IONet network via the VCMI (VME Communication Module Interface) or directly through the PPRO (Protection Processor) and TTUR (Turbine Terminal Unit Rack) assemblies. Each IS220 module is assigned a specific function within the rack and is not interchangeable across function types without corresponding software configuration changes in the Mark VIe Toolbox environment.

Early IS220 revisions (suffix AK, AL) used through-hole and mixed SMD component construction. Later revisions introduced conformal coating improvements for high-humidity environments. Firmware compatibility between hardware revisions must be verified before substitution — a critical step in any maintenance replacement procedure.

As GE Vernova pushes adoption of the Mark VIe-S (simplex) and Mark VIe-E (enhanced) platforms, IS220 hardware is no longer in active production for most module types. The installed base, however, remains substantial — with many plants operating under 15–25 year asset lifecycles that make platform migration economically unjustifiable in the near term.

IS220 Full Catalog & Functionalities (SKU List)

The following IS220 module types are documented within the Mark VIe platform. All SKUs listed are verified model designations within the GE IS220 family:

Digital Output Modules

• IS220YDOAS1AK: Digital output module, 24VDC sourcing, 16-channel, Mark VIe rack-mount
• IS220YDOAS1B: Digital output module, revised hardware revision B, 16-channel DO
• IS220PDOAH1A: High-density digital output module, protected DO channels

Digital Input Modules

• IS220PDIOH1A: Digital input/output combination module, 24VDC, Mark VIe
• IS220PDIAH1A: Digital input module, 24VDC, 16-channel DI, rack-mount
• IS220SDIOH1A: Simplex digital I/O module for Mark VIe-S architecture

Analog Input Modules

• IS220PAICH1A: Analog input module, 4–20mA / 0–10V, 16-channel AI
• IS220PAIAH1A: High-accuracy analog input module, thermocouple/RTD compatible
• IS220PTCCH1A: Thermocouple input module, cold junction compensation, 16-channel
• IS220PRPAH1A: Resolver/position input module for servo feedback applications

Analog Output Modules

• IS220PAOAH1A: Analog output module, 4–20mA, 8-channel AO, Mark VIe
• IS220PSVCAH1A: Servo control output module, electrohydraulic valve interface

Communication & Processor Modules

• IS220PSCAH1A: Serial communication module, RS-232/RS-485, Mark VIe rack
• IS220PTURH1A: Turbine terminal unit rack interface module
• IS220VCMIH2A: VME communication module interface, IONet Ethernet bridge
• IS220PPROS1A: Protection processor module, triple-redundant voting logic

Power Supply Modules

• IS220PSVOH1A: Power supply and voltage output module, rack-level distribution

Quality Control for the IS220 Range

IS220 modules interface directly with turbine protection and control logic. The consequences of a failed or counterfeit module in service range from nuisance trips to safety system impairment. Our QC process for IS220 hardware addresses the specific failure modes documented in GE's field service bulletins: