The GE IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board is a compact serial communication terminal board used within GE Industrial Control Systems. As a member of the SSCA board family, the IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board provides up to six communication channels, each of which may be configured for RS-232C, RS-485, or RS-422 signaling. The I/O pack plugs into the DC-62 pin connector to communicate with the Mark VIe controller over Ethernet, allowing the terminal board to serve as the field-side interface for multiple serial devices communicating with the control system.
The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board is identified by the GE part numbering convention used throughout the Industrial Control Systems product line. The "IS200" prefix identifies the board as a GE Industrial Control Systems product, with "200" specifically indicating that the board is a base-level assembly. The "SSCA" acronym identifies the board's functional designation as a Simplex Serial Communication Input/Output Terminal Board. The "H2" designation identifies the hardware group and the right-angle header configuration with pluggable terminal blocks, while the "ACB" suffix identifies the artwork and functional revision combination. All digits are important when ordering or replacing any board, as boards of different revision levels may not contain identical hardware, and GE ensures backward compatibility of replacement boards while noting that different revision levels may not contain identical components.
The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board is mounted on a DIN-rail using a sheet metal carrier and plastic insulator mount, and this assembly will also bolt directly into a cabinet. The board has a right-angle header accepting a range of commercially available pluggable terminal blocks with 48 terminals, distinguishing it from the SSCAH1 variant which has a permanently mounted terminal block. The board is designed for use with #18 AWG shielded twisted pair wiring, and the I/O cable shield termination is made on an external mounting bracket supplied by the customer or by GE. The chassis ground connection uses E1 and E2 as mounting holes, and one of the SCOM terminals (37–48) must be connected to a suitable shield ground.
This product introduction provides detailed technical information, functional descriptions, connector assignments, configuration guidance, and comprehensive specifications for the GE IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board, serving as an essential reference for control system engineers, maintenance technicians, and system integrators working with GE industrial control equipment.
Functional Architecture and Signal Processing
The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board is built around a flexible serial communication architecture that supports three different signaling standards across six independent channels. This architecture allows the board to interface with a wide variety of third-party devices, from short-distance RS-232C point-to-point connections to long-distance RS-422 and RS-485 multidrop networks, providing the flexibility required for diverse industrial communication applications.
The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board includes six connection points for each of the six serial communication channels. The points include four signal lines A through D, a signal return, and a shield common (SCOM). The signal assignments vary depending on the selected protocol. For RS-422, the signals are TX+ on A, TX− on B, RX+ on C, and RX− on D, with a cable length of up to 1000 feet. For RS-485, the signals are TX/RX+ on A and TX/RX− on B, with jumpers from A to C and from B to D, and a cable length of up to 1000 feet. For RS-232, the signals are DTR/RTS on A, TX on B, CTS on C, and RX on D, with a cable length of up to 50 feet or 2500 pF.
The return for RS-232C is through the terminal called RET. The signals for all six serial communication channels are arranged in the same order, which is SCOM, A, B, C, D, RET when viewed from left to right. The groups of six signals for a serial channel are assigned to terminals adjacent to each other. When viewed from left to right, the channels on the bottom set of terminals are five, four, and one, while the top set of terminals contain channels six, three, and two. The board SCOM connections are grouped on the right side of the terminals, and a signal location diagram is included on the SSCA to assist with wiring.
Termination and Return Ground Configuration
The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board provides comprehensive jumper-selectable termination and return ground options that allow each channel to be optimized for its specific application and cable environment.
When using RS-422 or RS-485, a termination resistor must be provided at either end of a transmission line. The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board provides selectable termination resistors for each pair of signal lines. Jumpers JP1A and JP1B apply or remove the termination resistors between signals A–B and C–D, and the same function is repeated for each serial communication channel. The default jumper position includes a disconnected termination resistor, and the SSCA is clearly marked to display the relationship of the termination jumpers and the serial communication channel signals.
In RS-232C systems, it is often not desirable to have a hard ground of the RET signal path on both ends of a cable. The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board includes jumper-selectable grounding options for each of the six RET lines. The line may be grounded through a 100 ohm resistor or through a 0.01 μF capacitor and 1 megohm resistor parallel combination. If the device attached to the SSCA has a hard ground of the RET line, the capacitive ground should be selected on the SSCA. If there is not a hard ground on the connected equipment, the resistive ground (default position) should be selected on the SSCA. The RET ground jumpers are identified on the SSCA as JP1R through JP6R, with positions displayed as RES and CAP for resistive and capacitive return connection.
Installation and Wiring
The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board is designed for straightforward installation in standard industrial cabinets. The board is mounted on a DIN-rail using a sheet metal carrier and plastic insulator mount, and the assembly will also bolt directly into a cabinet. There is no shield termination strip with this design; the I/O cable shield termination is made on an external mounting bracket supplied by the customer or by GE.
The board uses #18 AWG shielded twisted pair wiring, which provides excellent noise immunity for serial communication signals in electrically noisy industrial environments. The chassis ground connection uses E1 and E2 as mounting holes, and one of the SCOM terminals (37–48) must be connected to a suitable shield ground to ensure proper shielding and grounding of the communication cables.
The explicit terminal board screw connections for the six channels provide a clear and consistent wiring scheme. Channel 1 uses SCOM 26, A 28, B 30, C 32, D 34, and RET 36. Channel 2 uses SCOM 25, A 27, B 29, C 31, D 33, and RET 35. Channel 3 uses SCOM 13, A 15, B 17, C 19, D 21, and RET 23. Channel 4 uses SCOM 14, A 16, B 18, C 20, D 22, and RET 24. Channel 5 uses SCOM 2, A 4, B 6, C 8, D 10, and RET 12. Channel 6 uses SCOM 1, A 3, B 5, C 7, D 9, and RET 11. This consistent numbering scheme simplifies wiring and reduces the potential for errors during installation and maintenance.
Protocol Configuration and Connection Guidance
The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board supports three serial communication protocols, each of which requires specific jumper settings and wiring connections to interface correctly with third-party devices.
For RS-232C point-to-point connections, the board is configured with the RET ground jumpers in the default resistive position, and the connection between the SSCA and a third-party device follows the signal assignments of B (TX) to the third-party device RX, D (RX) to the third-party device TX, A (DTR/RTS) to the third-party device CTS, and C (CTS) to the third-party device RTS. The RET signal provides the return path for RS-232C. If a computer is connected as a test simulation device with MODSIM running, the wire from pin 5 of the D-type connector must be connected to SCOM1.
For RS-422 connections, the board uses the A (TX+), B (TX−), C (RX+), and D (RX−) signal assignments, and the termination jumpers JP#A and JP#B are set to IN at both ends of the transmission line to provide proper impedance matching. RS-422 supports cable lengths of up to 1000 feet and allows up to eight drops in a multidrop configuration.
For RS-485 half-duplex connections, the board uses the A (TX/RX+) and B (TX/RX−) signal assignments, with jumpers from A to C and from B to D. The termination jumper JP#A is set to IN and JP#B is set to OUT on the terminal board, and the C/D termination is left out. The A/B termination must be in, but the C/D termination must be out. The RS-485 half-duplex point-to-point connection requires a 120 ohm termination resistor at the SSCA end if the slave device does not have a termination resistor built in, and the RS-485 half-duplex multidrop connection requires a termination resistor at the SSCA and at the last device on the bus unless the device has a terminator built in.
Diagnostics and Board Identification
The JA connector on the IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board has its own ID device that is interrogated by the I/O pack. The ID device is a read-only chip coded with the terminal board serial number, board type, revision number, and J connector location. When this chip is read by the I/O processor and a mismatch is encountered, a hardware incompatibility fault is generated. This diagnostic feature ensures that the correct terminal board is installed in each location and that the system configuration matches the physical hardware, preventing incorrect operation and simplifying maintenance.
Application Suitability and System Integration
The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board is a versatile serial communication interface that can be used in a wide variety of GE Industrial Control System applications. Its six independent channels, each configurable for RS-232C, RS-485, or RS-422, allow the board to interface with multiple third-party devices, from short-distance point-to-point connections to long-distance multidrop networks, using a single terminal board.
In Mark VIe controller applications, the IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board serves as the field-side termination point for the serial communication channels, with the I/O pack plugging into the DC-62 pin connector to communicate with the controller over Ethernet. The board's configuration is performed partly through the on-board jumpers and partly through the ToolboxST application, with the electronic selection of the serial communications method internal to the I/O pack.
The board's DIN-rail mounting and sheet metal carrier simplify installation in standard control cabinets, and the right-angle header accepting commercially available pluggable terminal blocks allows for convenient field wiring and maintenance. The comprehensive jumper-selectable termination and return ground options allow each channel to be optimized for its specific application, ensuring reliable communication even in electrically noisy industrial environments.
Maintenance and Lifecycle
The IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board is designed for long service life with minimal maintenance. The board contains no moving parts, and its surface-mount construction ensures high reliability in continuous industrial operation. Routine maintenance consists of periodic visual inspection of the board, terminal blocks, and wiring, verification that the termination and return ground jumpers are set correctly for each channel, and confirmation that the SCOM terminals are properly connected to the shield ground.
The board's read-only ID chip provides automatic identification to the I/O pack, generating a hardware incompatibility fault if a mismatch is detected. This diagnostic feature simplifies troubleshooting and ensures that the correct board is installed in each location.
If the board requires replacement, the process is straightforward. After de-energizing the associated equipment and verifying that no power exists, the terminal block connections should be labeled and disconnected, and the board should be removed from its DIN-rail mounting. The replacement board should be installed in the same position, the jumpers set to match the original configuration, and the terminal blocks reconnected as labeled before returning the system to service.
GE Industrial Control Systems ensures compatibility of its replacement boards, even though boards of different revision levels may not contain identical hardware. When ordering a replacement IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board, provide the complete part number and description, the drive or system serial number, and the Material List (ML) number. The factory may substitute later versions based on availability and design enhancements, but backward compatibility of replacement boards is guaranteed.
Conclusion
The GE IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board is a reliable, robust, and versatile serial communication interface for GE Industrial Control Systems. Its six independent channels, each configurable for RS-232C, RS-485, or RS-422, its comprehensive jumper-selectable termination and return ground options, and its pluggable terminal block configuration provide the flexibility required for a wide range of industrial communication applications, while its read-only ID chip and surface-mount construction ensure reliable operation and straightforward maintenance.
With its DIN-rail mounting, clearly marked jumper and terminal assignments, and comprehensive documentation, the IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board is designed for easy installation, verification, and maintenance. Backed by GE's quality manufacturing, global support network, and commitment to backward compatibility, the IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board continues to deliver the performance, durability, and reliability that industrial users expect from GE. Whether used in a new installation or as a replacement for an existing board, the IS200SSCAH2ACB Simplex Serial Communication Input/Output Terminal Board provides the serial communication functionality required for reliable and efficient control system operation.
