Product Core Brief
- Model: IS220PPROS1B
- Brand: General Electric (GE)
- Series: Mark VIe (Speedtronic)
- Core Function: PROSO (Process Output) digital output module — provides isolated discrete output channels for driving relays, solenoids, and annunciators in gas/steam turbine control and industrial process applications.
- Product Type: PROSO Digital Output Module (I/O Pack)
- Key Specs: Multiple isolated digital output channels | Dual redundant Ethernet (IONet) | 28VDC power | TMR redundancy support | Hazardous location rated | Conformal coated
- Condition: New Original / New Surplus
Product Introduction
The GE IS220PPROS1B is a PROSO (Process Output) digital output module in GE’s Mark VIe Speedtronic control system, serving as the critical interface between the Mark VIe controller and field output devices such as relays, solenoid valves, alarm annunciators, and indicator lights. It converts digital control commands from the processor into isolated discrete output signals that drive external equipment.
The module is part of GE’s distributed I/O architecture, communicating with the Mark VIe processor (such as the UCSAH or UCSBH series) via dual redundant 10/100Mbps Ethernet ports (IONet). This ensures that output commands continue to reach the module even if one network cable fails. The PROSO module connects to a compatible terminal board via a DC-37 pin connector, which routes the field wiring to screw terminals for easy installation and maintenance.
The IS220PPROS1B features isolated output channels, meaning each output is electrically separated from the others and from the module’s internal circuitry. This isolation protects the module from voltage spikes, ground loops, and electrical noise that can occur in industrial environments — particularly important when driving inductive loads like solenoid valves and relay coils. The module is designed to operate in hazardous locations (Class 1, Division 2) when paired with compatible terminal boards, making it suitable for installation in turbine enclosures and other areas where flammable gases or vapors may be present.
In turbine applications, the PROSO module is commonly used for:
- Driving fuel shutoff solenoid valves
- Activating alarm and trip annunciators
- Controlling lube oil pump start/stop relays
- Operating cooling water valve actuators
- Triggering emergency shutdown (ESD) signals
The module supports Triple Modular Redundant (TMR) operation — when three PROSO modules are configured in a TMR arrangement, they vote on output states to provide fault-tolerant operation. If one module faults, the other two continue to drive the outputs correctly, preventing spurious trips.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Manufacturer | General Electric (GE) |
| Product Type | PROSO Digital Output Module (I/O Pack) |
| Series | Mark VIe (Speedtronic) |
| Output Type | Isolated discrete (digital) outputs |
| Communication | Dual redundant 10/100Mbps Ethernet (RJ45, IONet) |
| Terminal Board Interface | DC-37 pin female connector |
| Power Input | 28VDC |
| Redundancy | Simplex, Dual, TMR supported |
| Operating Temperature | -30°C to +65°C |
| Hazardous Rating | Class 1, Div. 2 (with compatible terminal board) |
| Conformal Coating | Yes (for harsh environment protection) |
| Certifications | CE, UL Listed, ATEX |
| Application | Turbine control relay driving, solenoid valve control, alarm annunciation, ESD signaling |
| Origin | USA |
Quality Control Process
Every IS220PPROS1B goes through a full functional bench test before it ships. We start with a visual PCB inspection — checking for cold solder joints, burnt traces, swollen capacitors, and verifying the integrity of the DC-37 pin connector and both RJ45 Ethernet jacks. We also inspect the conformal coating for any cracks or peeling that could compromise environmental protection.
Then we power it up on a regulated 28VDC supply and verify the power draw is within spec. We test each digital output channel by commanding it ON and OFF and measuring the output voltage with a multimeter, confirming that each channel switches correctly and that the isolation between channels is intact. We test the output drive capability by connecting a resistive load and confirming the module can source/sink the required current without voltage drop.
We test both Ethernet ports by connecting to a network switch and confirming link/activity LEDs illuminate on each port, then verifying the module registers on the IONet with its correct hardware ID. We test the redundant communication function by disconnecting one Ethernet cable and confirming the module continues to receive commands over the remaining link without interruption. We verify the TMR voting function by connecting three PROSO modules together and confirming they vote correctly on output states. We run a cycle test by rapidly switching each output ON/OFF for several hundred cycles, monitoring for contact wear or timing jitter. Finally, we confirm the module is compatible with the specified terminal board by performing a physical connection test. Each unit ships in anti-static foam with a moisture barrier bag.
Replacement Pitfall Guide
❗ Verify the terminal board compatibility before installation. The IS220PPROS1B must be paired with a compatible PROSO terminal board. Using an incompatible terminal board can result in incorrect wiring pinouts, potentially causing output signals to drive the wrong field devices — which could trigger an unintended turbine trip or fail to activate a critical safety function. Always confirm the terminal board model matches the PROSO module specification.
❗ Confirm the output channel configuration matches your application. The PROSO module’s output channels are configured in the ToolboxST software. If the replacement module’s channel configuration doesn’t match the original (e.g., different output types or different channel assignments), the controller may send commands to the wrong channels. After installing the replacement, verify the channel configuration in ToolboxST matches your application’s I/O map.
❗ Check the TMR voting configuration if applicable. If the PROSO module is part of a TMR output arrangement, all three modules must be properly configured as voting members. If the replacement is configured as a simplex unit, it will not participate in the voting logic, leaving your system without output redundancy. Verify the TMR configuration in ToolboxST after installation.
❗ Don’t skip the output drive test. After installing the replacement, test each output channel by commanding it ON and verifying the connected field device (relay, solenoid, annunciator) responds correctly. A module that communicates correctly but fails to drive outputs is a safety hazard — particularly for critical functions like fuel shutoff or emergency shutdown.
❗ Verify the isolation integrity. The PROSO module’s output isolation is critical for protecting the Mark VIe controller from field-side electrical faults. After installation, verify that there is no continuity between output channels and between outputs and the module ground. Compromised isolation can allow field-side voltage spikes to damage the controller or other I/O modules.
❗ Watch for Ethernet cable routing issues. The dual Ethernet ports provide redundant communication, but both cables must be routed through separate physical paths to provide true redundancy. If both cables run through the same cable tray and that tray is damaged, you lose both communication paths simultaneously. Route the primary and backup Ethernet cables through separate conduits or cable trays.
Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
| Original Model | Replacement / Successor Model | Compatibility Level | Migration Notes |
|---|---|---|---|
| IS220PPROS1C | Direct | Later revision; drop-in compatible | |
| IS220PPROS1A | Direct | Earlier revision; verify firmware match | |
| Mark VIe legacy PROSO | Direct | Drop-in for Mark VIe I/O racks | |
| IS420PDOH1B | Needs Adaptation | Mark VIeS variant; requires I/O network migration |
- Output Type: Isolated discrete outputs for relay/solenoid driving
- Redundancy: TMR support for fault-tolerant output operation
- Communication: Dual Ethernet ports for redundant IONet connectivity
