Description
GE IS200STCIH2A Simplex Contact Input Terminal Board
Product Overview
The GE IS200STCIH2A is a Simplex Contact Input (STCI) terminal board used in GE Mark VIe control systems to terminate and condition discrete field contact signals. The board accepts 24 contact inputs and provides the interface between field wiring and the associated Mark VIe discrete-input I/O pack. GE’s Mark VIe documentation describes the STCI as a compact contact-input terminal board designed for DIN-rail or flat mounting, with the PDIA I/O pack plugging into the board’s D-type connector.
The IS200STCIH2A is specifically the H2A version, which uses a pluggable terminal block and a nominal 24 VDC floating excitation supply. GE documentation specifies a 16–32 VDC range for this version. The field contacts are therefore not simply passive terminals; the board provides the excitation and signal-conditioning interface required for contact detection. The board incorporates filtering and noise suppression to reduce the effect of contact bounce, electrical transients, and high-frequency noise.
A key procurement distinction is that the IS200STCIH2A is a terminal board, not the discrete-input I/O processor itself. In the Mark VIe architecture, the associated PDIA I/O pack performs the conversion and communicates with the controller over Ethernet. The STCI provides the field termination and electrical interface. GE certification documentation explicitly lists IS200STCIH2A as an approved accessory terminal board for the Mark VIe PDIA discrete-input module.
Product Introduction
When a Mark VIe installation needs a straightforward 24-point simplex contact interface, the STCI architecture keeps the field wiring separate from the I/O processing electronics. The IS200STCIH2A provides the 24 VDC contact excitation and termination interface while the PDIA I/O pack handles the digital conversion and network communication.
For legacy Mark VIe replacement, the H2A suffix matters. It identifies the pluggable-terminal 24 VDC version, so substituting another STCI variant without checking excitation voltage and terminal configuration can create an avoidable wiring problem.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Product Model | |
| Manufacturer | General Electric |
| Product Family | Mark VIe |
| Product Type | Simplex Contact Input Terminal Board |
| Input Channels | 24 contact inputs |
| Input Type | Contact / discrete input |
| Terminal Block | Pluggable |
| Nominal Excitation | 24 VDC, floating |
| Excitation Range | 16–32 VDC |
| Mounting | DIN rail or flat/panel mounting |
| Associated I/O Pack | PDIA |
| System Configuration | Simplex |
| Input Filtering | Hardware filtering |
| Noise Protection | Surge and high-frequency noise suppression |
| Contact Input Current | First 21 circuits: approximately 2.5 mA each; last 3 circuits: approximately 10 mA each |
| Input Filter | Approximately 4 ms |
| Communication | Through associated PDIA I/O pack |
| Field Wiring | Directly to terminal block |
GE documentation specifies the STCIH2A as the 24 VDC floating, pluggable-terminal version. The detailed circuit-current and filter figures are also reported in technical descriptions of the Mark VIe STCIH2A.
Major Features / Practical Advantages
24 discrete contact inputs
The board provides 24 contact input circuits, allowing a single terminal board to collect a substantial number of discrete field signals. Typical applications include switch status, relay contacts, permissive signals, auxiliary contacts, and turbine-package discrete indications.
The inputs are designed around contact excitation rather than analog process measurement. That distinction is important when checking a replacement: this is not an analog input board and should not be specified by looking only at the number of terminals.
IS200STCIH2A
24 VDC floating excitation
The H2A version is designed around 24 VDC nominal floating excitation, with GE documentation specifying 16–32 VDC. A floating source is useful for discrete-input architectures where ground-fault detection and controlled field excitation are part of the system design.
Do not confuse this with the 48 VDC or 125 VDC STCI variants. GE documents the STCI family in several excitation-voltage versions, while the H2A specifically corresponds to the 24 VDC pluggable configuration.
Pluggable terminal block
The uses a pluggable terminal arrangement. This is a practical distinction during maintenance because field wiring can remain associated with a removable terminal assembly rather than requiring every conductor to be individually disconnected from the board during replacement.
Before ordering, compare the physical terminal arrangement against the installed board. Similar-looking STCI part numbers can represent different excitation voltages or terminal configurations.
Input noise suppression
GE documentation states that STCI contact inputs include noise suppression for surge and high-frequency noise. This is appropriate for turbine-control environments where long discrete wiring runs can pick up switching transients.
The published technical information also identifies approximately 4 ms hardware filtering on the inputs. That filtering is useful for rejecting short disturbances and contact bounce, although it should not be interpreted as a substitute for application-level debounce or sequence-of-events configuration.
Different current demand across circuits
The documented STCIH2A input arrangement does not draw identical current on every circuit. For 24 VDC applications, the first 21 circuits are specified at approximately 2.5 mA each, while the final three circuits are approximately 10 mA each.
That detail matters when calculating the excitation supply requirement, particularly if a large percentage of the 24 inputs are simultaneously energized.
PDIA I/O pack interface
The terminal board works with the Mark VIe PDIA discrete-input I/O pack. The I/O pack plugs into the terminal board and provides the processing and Ethernet communication path to the controller. GE’s certification documentation explicitly lists among the terminal boards compatible with the Mark VIe PDIA module.
This separation between termination hardware and processing hardware is fundamental to the Mark VIe architecture. Replacing an STCI board does not replace the PDIA I/O pack.
Simplex architecture
The STCI is specifically a Simplex Contact Input terminal board. GE’s Mark VIe guide states that the PDIA/STCI combination supports simplex systems.
This should be checked carefully when migrating an older control cabinet. A simplex STCI assembly should not be assumed to provide the same architecture as a dual or TMR contact-input terminal arrangement.
Related Products
- IS200STCIH1A — 24-input STCI variant with fixed terminal configuration. The H2A version uses a pluggable terminal block.
- IS200STCIH4A — 48 VDC STCI variant with pluggable termination. It should not be substituted for the H2A without checking the field excitation voltage.
- IS200STCIH6A — 125 VDC STCI variant intended for a substantially different contact-excitation voltage.
- IS220PDIAH1A — Mark VIe discrete-input I/O pack that interfaces with STCI terminal boards and performs the I/O processing/network interface.
- IS200TBCIH2C — Mark VIe contact-input terminal board for a different termination architecture; it should not be treated as a direct physical equivalent of the STCIH2A.
- IS200TBCIH4C — 48 VDC-class TBCI configuration listed by GE as another PDIA-compatible terminal board.
- IS200STCIS2A — Mark VIeS safety-system STCI variant using the YDIA safety I/O pack; its safety-system architecture differs from the Mark VIe .
- IS220YDIAS1A — Mark VIeS discrete-input I/O pack used with the safety-system STCI family rather than the standard Mark VIe PDIA arrangement.
FAQ
Can I replace an with an STCIH4A?
Not without an engineering check. The H2A is the 24 VDC version, while H4A is the 48 VDC version. The field excitation voltage and associated wiring must match the installed configuration.
Can I hot-swap the ?
Do not assume that the terminal board itself is universally hot-swappable. Replacement procedures depend on the Mark VIe cabinet architecture, I/O pack state, field energy, and site maintenance procedure. Isolate or otherwise place the affected circuit in the approved maintenance state before removing field-interface hardware.
Does the provide 24 digital inputs?
Yes, it provides 24 contact-input circuits. However, it is a terminal board, not the complete Mark VIe digital-input processing module. The associated PDIA I/O pack performs the digital I/O processing and Ethernet communication.
What excitation voltage does the H2A version use?
The documented H2A version uses 24 VDC nominal floating excitation, with a specified range of approximately 16–32 VDC. This is the key electrical distinction from the H4A and H6A versions.
Does it support 48 VDC contact inputs?
Not the H2A version. GE identifies a separate STCIH4A version for nominal 48 VDC excitation and an H6A version for nominal 125 VDC excitation.
Does the communicate directly with the controller?
No. The terminal board provides the field interface. The associated PDIA I/O pack plugs into the board and communicates with the Mark VIe controller over Ethernet.
Does it support firmware v3.1?
The part number does not establish a firmware revision. Firmware compatibility is principally relevant to the associated I/O pack and Mark VIe control configuration, so it should be checked against the installed PDIA and system revision rather than inferred from the terminal-board number.
Is the an analog input board?
No. Despite some inaccurate third-party listings that call it an analog board, GE documentation identifies the STCI as a Simplex Contact Input terminal board accepting 24 discrete contact inputs.
What is the difference between and IS200STCIS2A?
They belong to different Mark VI generations/architectures. is a Mark VIe contact-input terminal board used with the PDIA I/O pack, while IS200STCIS2A belongs to the Mark VIeS safety-system STCI family and is associated with the YDIA safety I/O pack. GE documentation distinguishes the two families.
Procurement Note
For an replacement, verify the complete field-interface assembly rather than matching the board number alone. Confirm that the existing installation uses 24 VDC floating excitation, the pluggable terminal configuration, 24 contact inputs, and the Mark VIe PDIA I/O pack.
The H2A suffix is particularly important. GE’s documentation distinguishes H2A from H1A, H4A, and H6A STCI versions according to terminal arrangement and excitation voltage. A visually similar board with a different suffix can therefore be electrically wrong for the cabinet.
For legacy spare procurement, inspect the actual board label, terminal connector, D-type I/O-pack connector, grounding points, and board revision. Confirm whether the offered unit is new surplus, refurbished, or previously installed. If the replacement is intended for a turbine control system that must remain operational, verify the associated PDIA I/O pack and controller configuration at the same time.
One final correction is worth emphasizing: the is not an analog-input module, an Ethernet communication module, or a standalone I/O processor. It is the field termination/interface board for 24 simplex contact inputs in the Mark VIe architecture. GE’s own Mark VIe documentation and certification records support that identification.
