Description
Product Overview
The GE IS200SDIIH1ADB (order number MRP683026) is a simplex discrete input terminal board from the GE Speedtronic Mark VIe I/O family. It is the passive wiring interface that sits between field devices and the active PDII input pack.
Field wires land on the green screw-terminal blocks along one edge. A mating PDII electronics pack plugs onto the D-sub connector on the other side. The board does no processing itself. Its job is to distribute wetting voltage, route contact signals to the pack, and provide optical isolation between the field wiring and the I/O electronics.
This split-pack architecture is standard across Mark VIe. The terminal board stays wired for the life of the plant. The electronics pack above it can be removed, upgraded or replaced without touching a single field wire.
The H1ADB suffix marks a specific simplex configuration within the SDII family. It supports configurable wetting voltage selection and serves dry-contact inputs from switches, relays, pushbuttons and auxiliary status contacts.
IS200SDIIH1ADB MRP683026
Core Product Features
- Accepts up to 24 discrete field input contacts on screw-terminal blocks, grouped for easy wiring and loop tracing.
- Configurable wetting voltage of 24 VDC, 48 VDC or 125 VDC, set by jumpers or strap options on the board, matching common plant control voltages.
- On-board opto-isolation channels block ground loops and surge energy between field wiring and the I/O pack.
- Rows of status LEDs above the terminal blocks show each channel’s live contact state during walkdowns and commissioning.
- The D-sub connector mates directly with a PDII input pack, so signal continuity between terminal board and pack is sealed and vibration-resistant.
- Field wiring remains fully seated when the electronics pack is removed, which cuts maintenance time and eliminates re-termination errors.
- Mounts on a standard Mark VIe I/O rack slot or panel, with screw-down mounting points for secure cabinet installation.
- PCB conformally coated for dust and moisture resistance in turbine hall and industrial environments.
Technical Specifications
| Item | Specification |
|---|---|
| Ordering model | IS200SDIIH1ADB |
| GE order number | MRP683026 |
| Product type | Simplex discrete input terminal board |
| Compatible platform | GE Speedtronic Mark VIe |
| Function | Field wiring termination and signal distribution for PDII input packs |
| Input channels | Up to 24 discrete contact inputs |
| Wetting voltage | Configurable: 24 VDC / 48 VDC / 125 VDC |
| Isolation | Optical, channel group to pack side |
| Pack connector | D-sub, mates with IS220PDIIH1B series pack |
| Field termination | Screw-terminal blocks |
| Status indicators | Per-channel LEDs |
| Configuration | Jumper-selectable wetting voltage |
| Mounting | Rack slot or panel mount, screw-down |
| PCB coating | Conformal coated |
| Compatible pack | IS220PDIIH1B (16-channel discrete input pack) |
| Humidity | 5% – 95% RH, non-condensing |
| Certifications | CE, UL, industrial EMC |
Channel count varies between 16 and 24 depending on the exact pack variant and wetting voltage configuration. The board physically supports up to 24 terminals, but a 16-channel PDII pack uses 16 of them. Match the pack and terminal board part numbers before ordering, and confirm the wetting voltage setting against the field supply.
IS200SDIIH1ADB MRP683026
Product Details and Application Fields
Product Details
Split architecture. This board is the bottom layer. The PDII electronics pack is the top layer. Field wires never touch the electronics. When a pack fails, you unplug it and plug in a new one. The wiring side never knows the difference.
Wetting voltage. Dry contacts need a small test voltage to detect closure. This board supplies that voltage from a plant control rail, selectable by strap. Choosing the wrong wetting level gives either false open states on long cables or unnecessary power dissipation on short ones.
Isolation strategy. Each channel group passes through an opto-coupler before reaching the pack connector. This is what keeps a field-side ground loop or a surge on a limit switch from propagating into the Mark VIe network.
LED layout. The red LEDs along the terminal row correspond one-to-one with field channels. During a startup walkdown, a technician can read contact state directly off the board without opening the HMI.
Revision context. H1ADB is the simplex variant. TMR systems use a different terminal board that fans one field contact across three pack inputs. Ordering the wrong one for a TMR rack leaves you with no way to wire the redundant channels.
Wiring discipline. Because the field wires stay put when the pack comes out, it is tempting to skip power isolation during pack swaps. The board still carries wetting voltage on the field terminals, so treat the terminals as live.
Application Fields
- Turbine interlock and protection contact termination in Mark VIe control cabinets
- Limit switch, pressure switch and auxiliary relay wiring for lube oil and hydraulic systems
- Emergency pushbutton and ESD contact termination in oil, gas and refining facilities
- Boiler and burner management discrete input marshalling in thermal power plants
- Mark VIe retrofit projects where existing field wiring is reused with new terminal boards
- Distributed I/O marshalling at compressor stations and pumping stations
- Spare terminal board stocking for plants standardising on the SDII / PDII I/O pair
Related Model Recommendations
- IS220PDIIH1B — the 16-channel discrete input electronics pack that plugs onto this terminal board; they are ordered and maintained as a matched pair.
- IS200SDIIH1B — base simplex discrete input terminal board without the ADB wetting voltage options, for standard 24 VDC installations.
- IS200SDTIH1A — TMR discrete input terminal board for triple-modular redundant protection channels, used when the system runs in three-out-of-three voting.
- IS220PDOAH1B — discrete output pack, paired with its own terminal board when the same IONet drop needs both input sensing and output driving.
