Model Breakdown

Full combined part number: IS220PDIOH1B 336A5026ADP6

IS220: Standard I/O assembly series prefix for Mark VIe systems, differentiating the hardware architecture from the legacy IS200 series.

PDIO: Abbreviation for Discrete Input Output, marking combined discrete input and output functionality.

H: Turbine-specific hardware revision, compatible with gas and steam turbine control logic.

1: First revision of the hardware baseboard.

B: Second optimized upgraded version. Compared with Revision A, it is fitted with RTV anti-vibration potting and stabilizing support bars to improve operational stability under vibrational conditions.

336A5026ADP6: Internal factory material order number for procurement, warehouse management and spare parts maintenance traceability. This code is uniformly applied to all batches of identical hardware with different packaging.

Product Specifications

Channel Configuration

24 channels of group-isolated 48VDC digital inputs; 12 channels of Form C dry-contact mechanical relay outputs.

Communication Specifications

Dual-channel 100 Mbps dedicated IONet Ethernet bus with automatic redundant switching. The front panel is equipped with four status indicators: ENET1, ENET2, PWR and ATTN.

Electrical Isolation

All input channels feature 1500 VAC optical isolation. Output relays adopt independent circuit isolation to eliminate leakage current interference.

Power Supply Parameters

Rated operating voltage: 28 VDC; minimum startup voltage: 27.4 VDC; the unit adopts a low power consumption design.

Event Logging Function

Native SOE (Sequence of Events) time sequence acquisition with 1 ms time resolution, fully recording the exact moment of every discrete signal state change.

Mechanical Construction

Standard rack-mountable design secured by bolts, compatible with standard Mark VIe I/O racks.

Certifications

UL, CE, Class I Division 2 and ATEX Zone 2 explosion-proof certifications.

Diagnostic Functions

Circuit wire break detection, relay contact fault diagnosis, and real-time reporting of communication link failures to ControlST software.

Relay Specifications

Form C break-make combined contacts capable of driving both AC and DC loads. External fuses can be installed to protect field circuits.

Product Advantages

Integrated combined input & output design. A single module handles both DI signal acquisition and DO actuator driving, reducing cabinet slot occupation while cutting hardware procurement costs and field wiring workloads.

Hardware redundancy via dual Ethernet ports. The IONet bus performs automatic link switching; control logic remains uninterrupted upon single port failure, complying with safety standards for continuous unit operation.

All input channels adopt 1500V optocoupler isolation, which effectively blocks AC and DC field noise interference and prevents system shutdown caused by high-voltage surges penetrating the main control board.

Relays feature pluggable socket construction. On-site maintenance only requires replacing faulty relays instead of the entire module to restore circuit operation, greatly shortening downtime for troubleshooting and repair.

Built-in Sequence of Events (SOE) logging function captures interlock action timestamps at millisecond precision, drastically improving efficiency in root-cause analysis for unit trips.

Wide-temperature rated hardware manufacturing. Continuous operation from 0℃ to +60℃ is approved by the manufacturer, with storage temperature tolerance ranging from -20℃ to +85℃. It fits air-conditioner-free cabinet environments for outdoor gas turbines and offshore platforms.

Full backward compatibility with the original IS220PDIOH1A. New and legacy modules can be mixed and installed in the same rack, eliminating the need for complete I/O backplane replacement during legacy system retrofits.

Full-channel diagnostic functions supported by matched ControlST software. Early warnings are generated for single-circuit open circuits, short circuits and worn relay contacts to enable predictive maintenance.

Applicable Industries

Main and auxiliary control systems for gas turbines in gas-fired power plants

Turbine interlock protection systems for steam power plants

Compressor units for long-distance oil & gas transmission pipelines

Turbine-driven equipment on offshore oil and gas platforms

Turbine unit control for coal chemical processes

Turbine control systems for fluid catalytic cracking units in refineries

Complete automatic control systems for large industrial compressors and blowers

Combined heat and power (CHP) units for distributed energy

Product Comparison

IS220PDIOH1B vs IS220PDIOH1A

Vibration resistance: Version 1B is equipped with RTV potting adhesive and reinforcing stabilizer bars, making it the preferred option for offshore platforms and high-vibration units. Version 1A has no anti-vibration reinforcement and is only applicable to stable indoor power plant cabinets.

Fault diagnosis: Version 1B expands monitoring algorithms for relay contact wear, while Version 1A only supports basic wire break alarms.

Compatibility: The two models are fully interchangeable in terms of backplanes, terminal boards and software configuration, and can be mixed in the same cabinet.

IS220PDIOH1B vs IS220PDOAH1B

Functional positioning: PDIOH1B is a combined DI+DO module for both signal acquisition and load driving; PDOAH1B is an output-only module without digital input channels.

Application scenarios: Select PDIOH1B for balanced signal points requiring both input collection and output drive circuits; choose PDOAH1B for centralized driving of mass solenoid valves with no signal acquisition requirements.

Rack slot occupation: PDIOH1B cuts slot usage by half under equivalent signal point demands.

IS220PDIOH1B vs IS220PDIIH1B

Functional positioning: PDIOH1B features relay outputs; PDIIH1B is an isolated digital input-only module with no output circuits.

Load capacity: PDIOH1B can directly drive field actuators; PDIIH1B merely collects discrete signals and cannot send control commands.

Supporting Products

IS200TDBSH4A 48V input terminal board (original standard wiring base)

IS215RIOAH1A standard Mark VIe I/O rack

IS220UCSAH1A IONet industrial Ethernet switch

ControlST unit configuration and diagnostic software

IS220PPDAH1B 28VDC system power supply module

Anti-static storage bags for modules and OEM replacement relay kits

Identical IS220PDIOH1B modules for TMR triple modular redundant configuration

Explosion-proof field junction boxes (for ATEX Zone 2 hazardous locations)

A1: IS220PDIOH1B refers to the hardware model, while 336A5026ADP6 is the factory material order number. Both codes must be provided for spare parts procurement to avoid incompatibility caused by mismatched baseboard versions from different production batches.

Q2: Can the original IS220PDIOH1A in legacy Mark VIe cabinets be directly replaced with IS220PDIOH1B? Is program modification required?

A2: Full compatibility is achieved in hardware, terminal boards and communication protocols. Direct plug-and-play replacement is available with no changes needed to ControlST configuration software; only diagnostic functions will be automatically upgraded.

Q3: What are the common root causes if the ATTN alarm indicator stays steady on after module power-up?

A3: Typical faults include short-circuit of field input circuits, aged or damaged relay contacts, single link disconnection among dual Ethernet ports, poor contact of backplane bus, and low 28VDC power supply voltage. Troubleshoot terminal wiring, Ethernet cables and rack power supply sequentially to pinpoint the issue.

Q4: Is periodic full module replacement required for long-term operation under high-vibration conditions on offshore platforms?

A4: Version 1B comes with built-in anti-vibration reinforced structure. Comprehensive inspection of relays is recommended every 3 to 5 years under normal operating conditions, with no full module replacement necessary. Annual dust cleaning of terminal boards and tightening of wiring bolts can extend service life.

Q5: If all 12 relay output channels of a single module fail, can separate relay spare parts be purchased instead of the whole module?

A5: Yes. Original factory independent pluggable relay spares are available. Replacing only defective relays drastically cuts spare part costs without replacing the entire I/O module.

Q6: Does this module support triple modular redundant (TMR) control architecture? How many identical modules are required for deployment?

A6: TMR triple redundancy is fully supported. Three sets of IS220PDIOH1B modules shall operate synchronously for one control loop, and the system adopts automatic 2-out-of-3 voting logic to guarantee control safety.