The DS200SDCCG4A is a Drive Control Card designed by General Electric (GE) Motors & Industrial Systems for its DIRECT-O-MATIC 2000 series control systems. Belonging to the SDCC (Drive Control Card) series, this board is part of the G4 group and represents revision A. It is specifically developed for TC2000 turbine control applications and serves as the core component for GE 2000 series control systems in the turbine control domain.
The primary function of the DS200SDCCG4A drive control card is to provide primary control for drives and motors, signal processing, and customer I/O interfaces. The G4 version is essentially identical to the G1A version, with the main differences being a larger EE parameter storage area and firmware specifically optimized for turbine applications. The board employs a three-processor architecture, including a Drive Control Processor (DCP), a Motor Control Processor (MCP), and a Co-motor Processor (CMP), which handle user interfaces and system-level functions, inner-loop current regulation and motor-specific functions, and math-intensive processing tasks, respectively. Onboard software is stored in five memory chips: four EPROMs (containing factory-programmed configuration data) and one EEPROM (containing field-adjustable parameters).
The DS200SDCCG4A board embodies GE’s advanced technology in turbine control and features the following characteristics:
Three-Processor Architecture: Integrates three 16-bit microprocessors handling control, application, and I/O functions respectively.
Extended EE Parameter Storage: Features larger parameter storage capacity compared to the G1A version, accommodating the extensive configuration parameters required for turbine control applications.
Turbine-Specific Firmware: Optimized for the specific needs of TC2000 turbine control systems.
Onboard Diagnostic LEDs: 10 LEDs display fault codes in BCD or binary mode, facilitating on-site troubleshooting.
Multiple Reset Options: Supports onboard pushbutton reset, external signal reset, software reset, and watchdog protection.
Rich I/O Interfaces: Provides multiple analog, digital, frequency, and communication interfaces.
This product is specifically designed for TC2000 turbine control systems, suitable for critical rotating equipment such as gas turbines and steam turbines. It is widely used in power plants, petrochemical facilities, natural gas transmission, and other industrial sectors.
II. Key Functions
1. Three-Processor Control Architecture
The DS200SDCCG4A card contains three 16-bit microprocessors that operate in coordination via dual-port RAM (DPR), a RAM configuration that can be independently and simultaneously accessed by two microprocessors:
| Processor | Location | Function Description |
| Drive Control Processor (DCP) | U1 | 80C186 microcontroller with numerous built-in peripheral functions, including address decoding (for chip selects), wait-state generators, an interrupt controller, timer/counters, and a direct memory access (DMA) controller. DCP software consists of user interfaces, outer regulating loops (such as speed and position), and system-level functions. In turbine applications, the DCP handles the core logic of turbine control. |
| Motor Control Processor (MCP) | U21 | 80C196 microcontroller with high-speed I/O, conventional digital I/O, analog I/O, timer/counters, and a watchdog timer. MCP software consists of inner loops such as current regulators, and motor/technology specific functions. In turbine applications, the MCP executes servo valve control and actuator regulation. |
| Co-motor Processor (CMP) | U35 | TMS320 C25 digital signal processor that performs math-intensive functions for motor control algorithms too complex for the MCP. Used only in drives requiring additional processing capability. The CMP interfaces only to its EPROM and MCP/CMP dual-port RAM. |
2. Onboard Software and Memory
The DS200SDCCG4A card stores software in five memory chips:
EPROMs (U11, U12, U22, U23): Four EPROMs containing factory-programmed configuration data, including turbine control application-specific algorithms and parameters.
EEPROM (U9): One EEPROM containing field-adjustable parameters. The G4 version features a larger EE parameter storage area compared to G1A, capable of holding the extensive configuration parameters required for turbine control.
Important Note: The DS200SDCC card (the version without memory chips) has empty sockets. When ordering a replacement board, specify the DS215SDCC card to ensure that the five memory chips are included. For the G4 version, memory chips specifically configured for turbine applications must be used.
3. LED Diagnostic Display
The DS200SDCCG4A card provides 10 diagnostic LEDs that display fault codes in a blinking mode:
| Fault Code Range | Display Mode |
| 1-399 | Slow blink rate BCD pattern (leftmost 2 LEDs encode the hundreds digit, next 4 LEDs encode the tens digit, rightmost LED encodes the units digit) |
| 400-1023 | Faster blink rate binary pattern (leftmost LED is 2^9=512, second LED is 2^8=256, and so on) |
| No fault or drive not running | Sequential blinking, two at a time, blinking from outer positions inward to center and back |
These same LEDs can be set by software jumper to also coarsely display drive variables when running (such as in absolute or signed bar graph mode). This setting does not inhibit the LED fault display. In turbine applications, these LEDs can be used for rapid diagnostics of the turbine protection system status.
4. Reset Circuits
The DS200SDCCG4A provides four reset methods, including a RESET pushbutton:
| Reset Method | Description |
| Onboard Button | Press the RESET pushbutton on the SDCC. |
| External Signal | Apply +5 to +24 V dc to customer interface points on the STBA or NTB/3TB boards (interfaced to the SDCC through 6PL). |
| Software Control | SDCC generates a reset via programmed software control. |
| Watchdog Protection | SDCC generates a reset via automatic internal hardware watchdog protection. |
Caution: A hard reset trips the system; the system should not normally be reset while running. In turbine control applications, reset operations must be performed with particular care to avoid affecting normal turbine operation.
III. Hardware Architecture
1. Card Groups
The DS200SDCCG4A card has three group numbers available (G2 versions were never manufactured). The G4 version is specifically designed for TC2000 turbine applications:
| Group | Application | Key Features |
| DS200SDCCG1A_ | AC2000, DC2000, EX2000 drive applications | Standard version for general drive and exciter applications |
| DS200SDCCG3A_ | DC1000 drives | Reduced functionality version |
| DS200SDCCG4A_ | TC2000 turbine applications | Same as G1A but with larger EE parameter storage and firmware optimized for turbine control |
2. Card Connectors
The DS200SDCCG4A interfaces with other controller boards and external signals via eight connectors (designated _PL):
| Connector | Interface | Purpose in TC2000 Applications |
| 1PL | I/O between the Power Supply/Interface Board (DS200IMCP, DCI, SDCI, or DCFB) and the SDCC | Connects power monitoring and protection signals |
| 2PL | ±5, 15, and 24 V dc inputs from the Power Supply/Interface Board to the SDCC | Provides control board operating power |
| 3PL | SDCC outputs to the LAN Communications Card (DS215SLCC) | Exchanges data with the LAN communication card |
| 6PL | I/O between the Drive Terminal Board (531X305NTB) or Simple Drive Terminal Board (DS200STBA) and the SDCC | Connects external I/O signals for turbine control |
| 7PL | I/O between the Signal Processor Card (531X309SPC) or Multibridge Signal Processing Card (DS200SPCB) and the SDCC | Processes encoder and position feedback signals |
| 8PL | I/O between the Drive Terminal Board (531X305NTB) or Simple Drive Terminal Board (DS200STBA) and the SDCC | Connects digital inputs and encoder signals |
| 9PL | Not used | — |
| 11PL | SDCC outputs to meters | Drives meter displays |
3. Auxiliary Board Mounting
The DS200SDCCG4A has mounting provisions for other auxiliary boards and modules. The following boards can be mounted on the SDCC:
DS215SLCC or 531X306LCC LAN Communications Card
531X309SPC Signal Processor Card
DS200SPCB Multibridge Signal Processing Card
In TC2000 turbine applications, a LAN communication card is typically required to communicate with other components of the turbine control system.
4. Testpoints
The DS200SDCCG4A provides multiple onboard testpoints for test and troubleshooting:
| Testpoint | Name | Description |
| DCOM1/DCOM2 | Common reference | 0 volt common reference point |
| P5 | +5 V power | Regulated +5 V power supply (±5%) |
| TP4 | DCP foreground timing flag | 720 Hz |
| TP5 | DCP blockware timing flag | 720 Hz |
| TP6 | DCP slow background timing flag | 90 Hz |
| RTS | General purpose testpoint | General purpose testpoint output from DCP |
| TP8 | Phase current | Analog representation of phase A motor current, with a nominal dc offset of +2.5 V |
| FCLK | Oscillator output | “I’m alive” 8 MHz oscillator output from MCP |
| NMI | Board test | Initiates board test (Test 13) when momentarily tied to +5 V. For board test only. |
| DACS | D/A daughterboard select | Diagnostic D/A converter daughterboard select |
| N15 | -15 V power | Regulated -15 V power supply (±5%) |
| P15 | +15 V power | Regulated +15 V power supply (±5%) |
| TP29 | Input line frequency | Testpoint for input line frequency |
| TP37 | DC voltage | Testpoint for dc voltage (not used on ac drives) |
IV. Key Differences from G1A Version
| Feature | G1A Version | G4A Version |
| Primary Application | AC2000, DC2000, EX2000 drive and exciter systems | TC2000 turbine control system |
| EE Parameter Storage | Standard capacity | Extended capacity |
| Firmware | General drive/exciter firmware | TC2000 turbine control specific firmware |
| Parameter Configuration | Drive/exciter parameters | Turbine control parameters (overspeed settings, temperature protection, etc.) |
| Functional Focus | Motor control, speed regulation, current regulation | Turbine protection, fuel control, overspeed monitoring |
| Software Jumpers | Some jumpers for drive function configuration | Some jumpers for turbine-specific function configuration |
V. Configuration and Settings
1. Hardware Jumper Configuration
The SDCC includes various configurable hardware jumpers, most of which are factory-set. The G4 version has essentially the same jumper settings as the G1A version, but with configurations tailored to turbine application requirements:
| Jumper | Function | Default Position | Description in TC2000 Applications |
| JP1 | EEPROM write protect | 2.3 (write enabled) | 1.2 = write inhibited (safe mode). Write enable is recommended in turbine applications to allow parameter modification. |
| JP7 | Feedback VCO gain | 1.2 (normal gain) | 2.3 = increase gain 6:1; select based on turbine feedback signal type. |
| JP8 | Feedback VCO absolute value circuit | 1.2 (bipolar mode) | 2.3 = absolute mode for AC tachometer applications. |
| JP15 | DCP crystal enable | 1.2 (enabled) | Must remain enabled to ensure DCP proper operation. |
| JP16 | FLASH program mode | 1.2 (normal read mode) | 2.3 = FLASH reprogramming mode; used only during firmware upgrades. |
| JP22 | MCP crystal enable | 1.2 (enabled) | Must remain enabled to ensure MCP proper operation. |
| JP23 | DCP DMA channel signal source | 1.2 (from NTB/3TB analog feedback) | 2.3 = from encoder marker input; select based on turbine feedback signal type. |
| JP33 | CMP crystal enable | 1.2 (enabled) | Must remain enabled to ensure CMP proper operation. |
2. Wire Jumper Configuration
| Jumper | Function | G4A Position | Description |
| WJ1 | Map MET3 D/A to DAC1 | 0 (jumper omitted) | SDCCG1 characteristic |
| WJ2 | Map MET4 D/A to DAC2 | 0 (jumper omitted) | SDCCG1 characteristic |
| WJ3 | 10 V full scale reference for D/A outputs | 0 (jumper omitted) | SDCCG1 uses internal reference from 12-bit D/A |
| WJ4 | Identify card group to firmware | 0 (jumper omitted, identifies G1) | Firmware uses this jumper to identify card group |
| WJ5 | Configure logic cell array size | 1.2 (jumper installed) | SDCCG1 uses 3064 device |
| WJ7-WJ10 | Configure EEPROM size | As per Table 2 | Specific configuration for all present drive applications |
3. Software Configuration Tools
Any adjustment, downloading, or replacement of software on the SDCC requires the use of one of the following tools:
ST2000: A DOS-based set of software tools for configuring GE DIRECT-O-MATIC® 2000 control equipment.
GE Control System Toolbox: A Windows-based set of software tools for configuring GE DIRECT-O-MATIC® 2000 control equipment.
LynxOS Drive Configurator: A set of software tools designed to run on a personal computer operating with the LynxOS operating system.
For TC2000 turbine applications, the specific TC2000 configuration manuals should also be referenced.
VI. Installation and Maintenance
1. Installation Steps
Power Off: Turn off power to the drive, wait several minutes for power supply capacitors to discharge, and test to verify that no power exists.
Open Cabinet Door: Access the printed wiring board area.
Disconnect Cables: Carefully disconnect all cables; verify that cables are labeled to simplify reconnection.
Remove Auxiliary Boards: If any auxiliary boards are mounted, remove the mounting screws and take off the auxiliary boards.
Release Snaps: Push back the plastic snaps to remove the old card.
Move Standoffs: Transfer standoffs from the old card to the new card.
Configure New Card: Set all configurable components on the new card to the same positions as on the card being replaced.
Install New Card: Install the new SDCC card, ensuring all snaps snap into position.
Reconnect Cables: Reconnect all cables as labeled, ensuring they are properly seated at both ends.
Install Auxiliary Boards: Reinstall any auxiliary boards and connect cables.
Install Programmer Module: If applicable, plug the keypad into the KPPL connector and snap the cover into place.
2. Replacing/Inserting Software
When replacing an SDCC:
Transfer the four EPROMs (U11, U12, U22, U23) from the old card to the new card.
Transfer the EEPROM (U9) from the old card to the new card.
If the failure symptoms persist, install new EPROMs and a blank EEPROM (shipped with the new card if it is a DS215SDCC) and program the EEPROM using software tools.
Important Note: Because the G4 version features larger EE parameter storage, when upgrading from a G1A version, an EEPROM specifically configured for the G4 version must be used.
3. Maintenance Recommendations
ESD Precautions: Always wear a grounding strap when handling boards. Store boards in anti-static bags.
Periodic Inspection: Check connectors for looseness and plastic snaps for secure fastening.
Parameter Backup: Regularly back up the turbine control parameters stored in the EEPROM to prevent accidental loss.
Spare Parts Management: It is recommended to keep at least one identical SDCC card on-site as a spare to minimize downtime.
Firmware Updates: When updating firmware, strictly follow GE official procedures to avoid power interruption during the process.
VII. Applications
The DS200SDCCG4A Drive Control Card is specifically designed for the following industrial applications:
TC2000 Turbine Control System: As the core control component of the TC2000 system, providing complete control functions for gas turbines and steam turbines.
Gas Turbine Control: Executes fuel control, speed control, temperature monitoring, combustion monitoring, and other turbine control functions.
Steam Turbine Control: Executes turbine speed governing, protection, and load control.
Generator Protection Systems: Interfaces with generator protection devices for voltage and reactive power regulation.
Combined Cycle Power Plants: Coordinates gas turbine and steam turbine operation in multi-shaft or single-shaft configurations.
Industrial Turbine Drives: Provides control functions in turbine drive systems for compressors, pumps, and other industrial equipment.
