Key Technical Specifications
| Parameter | Value |
|---|---|
| Product Model | IS220YDOAS1A |
| Product Family | GE Mark VIe / Mark VIeS |
| Function Acronym | YDOA |
| Product Type | Discrete output I/O pack |
| Output Capacity | Up to 12 relay outputs |
| Feedback Monitoring | Relay and fuse feedback from terminal board |
| Communication | Up to two I/O Ethernet networks |
| Connector | DC-37 to compatible terminal board |
| Redundancy Mode | Simplex (1 pack) or TMR (3 packs) |
| Diagnostics | Power-on self-test; ToolboxST diagnostics |
| Ambient Temperature | -30 to +65 °C |
| Software Support | ToolboxST / ControlST V06.01 and later |
| Typical Reference | GEH-6725 |
| Condition | New Original / New Surplus / Refurbished (Tested) |
| Warranty | 12 months |
Product Introduction
GE IS220YDOAS1A is a Mark VIe discrete output I/O pack used in GE turbine and critical process control systems. It receives output commands over the I/O Ethernet network and drives discrete relay outputs through a connected terminal board.This pack is typically deployed in Simplex or TMR configurations, with one pack per channel in Simplex and three packs per TMR group. It supports up to 12 relay outputs and monitors relay/fuse feedback to help detect open circuits, blown fuses, or missing terminal-board excitation. Status is visible through front LEDs — yellow indicates an active output command — and detailed diagnostics appear in ToolboxST. Exact terminal-board pairing and power requirements must be confirmed from the installed system, because Mark VIe I/O packs depend on the terminal-board ID chip and application configuration.
Installation & Configuration Guide
Preparation — 10 min
- Record controller tag, I/O pack slot, terminal-board type, and serial number.
- Photograph the nameplate, LEDs, DIP/jumper settings, and Ethernet cable positions.
- Confirm the replacement IS220YDOAS1A matches the application: YDOA function, firmware level, and terminal-board type.
- Back up the Mark VIe configuration in ToolboxST / ControlST before any hardware change.
- Verify the terminal board is mechanically secure and the DC-37 connector is clean.
Removal — 5–10 min
- Move affected outputs to a safe state per plant procedure.
- Follow site lockout/tagout rules.
- Disconnect Ethernet cables and the power connector.
- Remove mounting hardware and pull the pack straight out of the terminal-board connector.
Installation — 10 min
- Inspect the DC-37 connector for bent pins or carbon tracking.
- Seat the IS220YDOAS1A fully before tightening mounting studs.
- Reconnect Ethernet cables; note ENET1/ENET2 position for TMR systems.
- Reconnect the power connector.
- Do not force the pack. A misaligned DC-37 connector can damage both sides.
Power-On & Test — 10 min
- Measure supply voltage at the power connector before energizing.
- Power up and check LED status.
- Confirm the pack appears in ToolboxST with correct type and firmware.
- Verify output commands, relay feedback, and fuse-monitor alarms.
- Check for Alarm 142 or similar “no terminal-board excitation / all fuses blown” indications before returning to service.
Troubleshooting Quick Reference
| Symptom | Most Likely Cause | First Check |
|---|---|---|
| No LEDs after power-up | Missing or low supply voltage | Measure power at the pack connector |
| Output does not energize | Open fuse, wiring fault, or disabled command | Check terminal-board fuses and output status in ToolboxST |
| Alarm 142 present | No terminal-board excitation or all fuses blown | Verify terminal-board power and fuse continuity |
| Pack not seen on network | Ethernet cable, port, or address issue | Reseat Ethernet cables; verify network link LEDs |
| TMR disagreement | One pack lagging or faulty feedback | Compare diagnostics across all three YDOA packs |
| Intermittent output | Loose DC-37 connector | Power down, reseat pack, inspect connector pins |
Dimensions, Mounting & Wiring Notes
- Dimensions: Not confirmed from verified OEM data for IS220YDOAS1A. Use the original pack as a mechanical reference.
- Mounting: Mounts directly to a compatible Mark VIe discrete output terminal board via DC-37 connector; secured with mounting studs near the Ethernet ports.
- Terminal Notes: The DC-37 connector carries output and feedback signals. Terminal-board compatibility is determined by the board ID chip and application configuration.
- Wiring Notes: Keep Ethernet cables away from high-current power runs. Confirm power polarity and terminal-board excitation voltage before enabling outputs.
FAQ
Can I replace IS220PDOAH1A with IS220YDOAS1A?
Not automatically. Both are Mark VIe discrete output packs, but YDOA and PDOA may differ in firmware, terminal-board support, and application use. Match the installed function code and ToolboxST configuration before substitution.Does IS220YDOAS1A work in TMR?
Yes. TMR applications require three YDOA packs, one per redundant channel. Simplex applications use one pack.What software do I need to configure it?
ToolboxST / ControlST V06.01 or later is typically required for YDOA diagnostics and configuration.I see Alarm 142 after replacement. What does that mean?
It usually indicates missing terminal-board excitation or blown fuses. Check terminal-board power, fuse status, and wiring before replacing the pack.Is this module still produced by GE?
Many Mark VIe I/O packs remain supported, but availability depends on revision and supply channel. Surplus and tested stock are common for legacy replacements.Do you test these before shipping?
Function is verified under test conditions when tested stock is supplied. That includes visual inspection, supply check, connector inspection, communication check, and basic I/O verification. Full turbine-system testing is not performed unless specifically arranged.What warranty do you offer?
12 months, unless otherwise stated on the quotation. Condition — New Original, New Surplus, or Refurbished (Tested) — is confirmed per unit.
