The IS200DSPXH2C is a Digital Signal Processor Control Board designed by General Electric (GE) for its Innovation Series™ Drives and EX2100™ Excitation Control System. This board is an important hardware revision within the DSPX series, belonging to the H2 hardware family. It serves as the primary controller for bridge and motor regulator functions, gating functions, and generator field control functions, playing a central role in industrial control systems.
The IS200DSPXH2C board integrates a high-performance Digital Signal Processor (DSP), standard memory components, and an Application Specific Integrated Circuit (ASIC) that performs custom logic functions. It operates at a 60 MHz clock speed, providing powerful computational capability for real-time processing of complex control algorithms. The board is equipped with various types of memory, including FLASH memory for booting and code execution, RAM for data storage, NVRAM for non-volatile data storage, and read-only memory for board revision identification.
Key features of the IS200DSPXH2C include:
High-Performance DSP: 60 MHz clock speed, providing powerful real-time processing capability.
Multiple Memory Types: FLASH, RAM, NVRAM, and read-only memory.
Dedicated ASIC: Integrates custom logic functions, enhancing system integration and reliability.
Rich Communication Interfaces: Includes ISBus, TTL serial interfaces, HIFI differential inputs, etc.
Flexible I/O Configuration: Supports VCO counters, quadrature incremental encoder interfaces, discrete inputs, and more.
Precise Synchronization Functions: Inner loop and application loop load pulse signals ensure accurate control timing.
Comprehensive Protection Mechanisms: Stack overflow detection, watchdog timer, ensuring safe system operation.
Status Indication: Front panel FAULT and STATUS LEDs provide intuitive operational status.
The board connects to the backplane via a 4-row, 128-pin DIN connector (P1). In the EX2100 excitation system, it works in conjunction with the EISB board, with the two physically attached to form a single unit. The front panel also provides a DSP emulator port (P5) and an engineering monitor port (P6) for development and maintenance. As part of the H2 hardware family, the IS200DSPXH2C, while maintaining core functionality, may differ in certain hardware characteristics or interface definitions from the H1 series to suit specific application requirements.
II. Main Functions
The primary functions of the IS200DSPXH2C include, but are not limited to, the following:
1. Digital Signal Processing and Control
The core of the IS200DSPXH2C board is a high-performance Digital Signal Processor running at 60 MHz, responsible for executing control algorithms, processing input signals, and generating output commands. In Innovation Series drives, it controls bridge and motor regulation and gating functions. In the EX2100 excitation system, it controls generator field excitation functions.
2. Support for Multiple Memory Types
The board provides various memory types to meet different application requirements:
FLASH Memory: Stores DSP boot images, code for execution, configurable parameters, and system history records.
RAM: Used for data storage and code execution.
NVRAM: Used for non-volatile data storage, ensuring data retention after power loss.
Read-Only Memory: Stores board revision identification information.
3. Dedicated ASIC Logic
The ASIC on the board integrates most specialized and support functions, including:
ASIC revision identification register.
Serial interface control.
Load pulse signal synchronization.
Stack overflow detection.
Watchdog timer.
24-bit free-running timer.
Counters and capture registers.
PWM outputs.
4. Serial Communication Interfaces
The IS200DSPXH2C provides four serial interfaces via the P1 connector:
Two ISBus Interfaces: 5 Mb/s rate, configurable as master or slave, for communication with ACL or local expansion functions.
One TTL Asynchronous Interface: For connecting a PC-based configuration tool, including RX, TX, and TXEN/RTS signals.
One TTL Asynchronous Interface: For connecting a programmer board, including RX, TX, and RTS signals.
5. Synchronizing Load Pulse Signals
The board uses load pulse signals for precise synchronization control:
Inner Loop Load Pulse: Captures I/O values such as bridge, motor, or generator voltage/current VCOs, tachometer counters, and discrete inputs. It can also synchronize ISBus channels, software, and gating outputs.
Application Loop Load Pulse: Operates at a sub-multiple or multiple of the inner loop load pulse frequency, used to capture values of other application VCOs and tachometers.
To facilitate firmware synchronization, a 6-bit register is provided. It increments on each inner loop load pulse and resets on each application loop load pulse.
6. Stack Overflow Detection
The board provides overflow detection for the foreground stack (using internal memory) and the background stack (using external SRAM). An overflow in either stack generates interrupt INT0. If both stacks overflow simultaneously, a hard reset is generated. A configuration register allows the stack overflow reset to be disabled.
7. Watchdog Timer
The watchdog timer is enabled and must be periodically toggled by the DSP (toggle interval is configurable). A watchdog timeout will generate a hard reset, ensuring the system can automatically recover from software anomalies.
8. HIFI Differential Inputs
The board provides five differential (HIFI) application inputs, configurable for one of three modes:
Two Quadrature Incremental Encoder Interfaces: One with marker capability, driving two 16-bit up/down counters. Counters maintain their state when inputs are at the same level and change state when inputs are differentially opposite. Each counter change is accompanied by a 5 MHz timer reset and a state register recording the count direction. Capture registers can be configured to capture values on the occurrence of either the inner loop or application loop load pulse.
Application Layer VCO Counters or Single-Channel Latch Interfaces: Five 16-bit counters increment on the differentially decoded and filtered inputs. These counter values are captured into registers by the application loop load pulse for the DSP to read.
Up to Ten Discrete Inputs: Each input is filtered for three system clock cycles and is directly readable by the DSP in a buffer.
9. Bridge VCO Inputs
Six inputs from the backplane are digitally filtered and input to the VCO counters. These are 16-bit counters with capture registers latched by the inner loop load pulse and readable by the DSP. The inputs come from technology-specific I/O cards such as BIC (bridge interface) or exciter interface cards.
10. PWM Outputs
The board provides two PWM outputs at a fixed frequency of 24 kHz with 10-bit resolution each, occupying one 20-bit register. They can be used to drive instrumentation meters or other outputs.
11. Expansion Board I/O
A SYNC OUT signal is provided for synchronizing functions at the BIC board layer.
III. System Applications
1. Application in Innovation Series Drives
In Innovation Series drives, the IS200DSPXH2C acts as the main controller, responsible for:
Bridge Control: Controls the switching state of the power bridge to achieve motor speed and torque control.
Motor Regulation: Executes motor control algorithms, processes feedback signals, and generates gate firing pulses.
Real-Time Processing: Acquires and processes VCO inputs, tachometer counters, and other signals at high speed.
Communication Interface: Communicates with ACL or other expansion modules via ISBus.
2. Application in EX2100 Excitation Control System
In the EX2100 excitation control system, the IS200DSPXH2C works in conjunction with the EISB board, responsible for:
Generator Field Control: Executes Automatic Voltage Regulator (AVR) algorithms to control field current.
Inner Loop Control: Processes field voltage and current feedback, generates gate firing commands.
Protection Functions: Monitors system status, implements over-excitation, under-excitation, V/Hz limiting, and other protection functions.
Redundancy Support: In TMR systems, works with M1, M2, and C controllers to achieve redundant control.
3. Coordination with the EISB Board
In the EX2100 system, the IS200DSPXH2C and EISB board are physically attached to form a single unit:
EISB Functions: Provides ISBus communication, fiber optic interfaces, keypad and tool ports.
Signal Exchange: DSPX exchanges data with EISB via the backplane to communicate with external devices.
Integrated Replacement: During maintenance, the DSPX and EISB are typically removed from the rack as a single unit.
4. Characteristics of the H2 Series
As part of the H2 hardware family, the IS200DSPXH2C may feature:
Enhanced Interface Capabilities: May offer different signal definitions or additional functional support on the P1 connector.
Optimized Hardware Design: Hardware optimizations for specific application scenarios, such as higher noise immunity or a wider operating temperature range.
Compatibility: Remains software-compatible with H1 series boards, but version matching is important during hardware replacement.
5. Typical Application Scenarios
Industrial Drive Control: Core control for various AC variable frequency drives.
Generator Excitation Control: Automatic voltage regulation for synchronous generators.
Process Control: As a high-performance controller for industrial process control requiring real-time processing.
Power System Stabilization: Works with PSS functions to improve power system stability.
IV. Detailed Interface Description
1. P1 Backplane Connector
P1 is a 4-row, 32-pin DIN connector (128 pins total), providing all signal connections between the DSPX and the backplane and other boards. As an H2 series board, certain pin definitions on P1 may differ slightly from the H1 series; refer to the relevant technical documentation for details. Key signal categories include:
| Signal Category | Quantity | Description |
| Data Bus | 32 bits | D0-D31, bidirectional data bus |
| Address Bus | 14 bits | A0-A13, address bus |
| Chip Selects | 4 | 0CS_BIC, 0CS_IO, 0CS_LAN, 0CS_SPR, select BIC, I/O, LAN, and spare boards respectively |
| Bus Control | 2 | OBUS_RD (Bus Read), OBUS_WR (Bus Write) |
| Interrupt Inputs | 4 | INT_BIC, INT_IO, INT_LAN, etc. |
| VCO Inputs | 6 | VCO_1 to VCO_6, 0-2 MHz bridge VCO inputs |
| HIFI Inputs | 5 pairs | HIFI_1P/N to HIFI_5P/N, differential inputs |
| ISBus Interfaces | 2 | GR1_TX/RX, GR2_TX/RX, 5 Mb/s serial communication |
| Load Pulses | 3 | Inner loop and application loop load pulses, etc. |
| Keypad Interface | 3 | KYPD_TX, KYPD_RX, KYPD_RTS |
| Tool Interface | 3 | TOOL_TX, TOOL_RX, TOOL_TXEN |
| PWM Outputs | 2 | MTR1_PWM, MTR2_PWM, 24 kHz, 10-bit resolution |
| SYNC_OUT | 1 | For LAN synchronization |
| Clock Outputs | Multiple | CPU_CLK1/2, CLK20_1/2, CLKT0/1/2, etc. |
| Power | Multiple | P5 (+5 V), DCOM (Digital Power Return), ACOM (Analog Power Return) |
2. P5 Emulator Port
P5 is located on the board's front panel and provides an interface to the TI emulator port. It is a scan interface (similar to JTAG) that supports emulation and FLASH programming.
3. P6 Engineering Monitor Port
P6 is located on the board's front panel and connects to the DSP's synchronous serial port (TTL levels). It is for GE engineering use only.
4. Onboard Test Points
P6 and P7 (located on the board surface) are test points for test/development use only and should not be used for field maintenance.
5. Front Panel LEDs
| LED | Color | Normal State | Abnormal State |
| FAULT | Red | Off | On or flashing: Fault occurred or during reset |
| STATUS | Green | Flashing (Running) | Steady On: Stopped; Off: Fault occurred or during reset |
V. Indicators and Diagnostics
1. FAULT LED (Red)
Directly driven by the DSP, indicates board fault status:
Off: No faults, normal operation.
On or Flashing: A fault has occurred, or the board is in reset.
2. STATUS LED (Green)
Driven by the DSP, indicates board operational status:
Flashing: Board is running.
Steady On: Board has stopped.
Off: A fault has occurred, or the board is in reset.
3. Diagnostic Functions
The IS200DSPXH2C implements various diagnostic functions through internal logic and firmware:
Stack Overflow Detection: Prevents system crashes due to software anomalies.
Watchdog Timer: Ensures software responds within a predetermined time.
Memory Checks: Integrity checks for FLASH and RAM.
Communication Interface Monitoring: Status monitoring for ISBus and serial interfaces.
Power Supply Voltage Monitoring: Monitors critical power supply voltages via the backplane.
Diagnostic results can be read via Toolbox software, and preliminary indication is available from the front panel LEDs.
VI. Installation and Replacement
1. Mounting Location
The IS200DSPXH2C board inserts into a designated slot in the control rack. In the EX2100 system, the DSPX is physically attached to the EISB board, with DSPX on top and EISB below. During installation, ensure the board is inserted into the correct slot; incorrect insertion may damage board electronics.
2. Offline Replacement Procedure (System De-energized)
Safety Warnings:
WARNING: To prevent electric shock, turn off power to the system and follow the complete de-energizing and discharge procedures outlined in the relevant guides. Adhere to all local Lock-out/Tag-out practices.
CAUTION: To prevent component damage caused by static electricity, treat all boards with static sensitive handling techniques. Wear a grounding strap and store boards in anti-static bags.
Replacement Steps:
Verify Power Off: Ensure the system is completely de-energized. Open the control cabinet door and check that power indicators on the EPDM (if present) and EPSM are off, and the LEDs on the DSPX are off.
Disconnect Fiber Optics: Disconnect the six fiber-optic cables from the EISB front panel.
Remove Old Board(s):
Loosen the screws at the top of the DSPX faceplate and the bottom of the EISB faceplate near the ejector tabs (screws are captive).
Unseat the DSPX and EISB by raising the ejector tabs.
Gently pull both boards together from the rack using both hands.
Separate EISB: Remove the EISB from the bottom of the DSPX and attach it to the replacement DSPX.
Install New Board(s):
Align the new DSPX and attached EISB with the correct slot and push them in along the guides.
Using thumbs, firmly press the top and bottom of the faceplates simultaneously to initially seat the boards.
Alternately tighten the screws at the top and bottom of the faceplate assembly evenly to ensure the module is squarely seated.
Reconnect Fiber Optics: Reconnect all communication cables disconnected in step 2.
Restore Power: Close the cabinet door and restore power to the system.
Reconfigure: After the DSPX is replaced, it must be reconfigured. Refer to the Toolbox software for required procedures.
3. Online Replacement Procedure (Redundant System)
In a redundant control system, a failed DSPX board can be replaced while the system is running.
Risk Warning: During online replacement, other controllers, power supplies, and terminal boards remain energized and active. Extreme caution must be taken to avoid touching other live parts or causing short circuits.
Replacement Steps:
Identify Failed Board: Confirm the section (M1, M2, or C) containing the failed DSPX via front panel indicators.
De-energize Section: Following procedures for the specific EX2100 type, turn off power to the section containing the failed DSPX. Check that the LED indicators on the corresponding EPSM section are off.
Verify Control Transfer and Power Off: Check controller LEDs to confirm control has transferred to the other master. Verify that all power indicators on boards in the affected section are off before touching the DSPX.
Disconnect Fiber Optics: Disconnect the fiber-optic communication cables from the EISB front panel.
Remove Failed Board(s): Same as offline procedure.
Separate EISB: Same as offline procedure.
Install New Board(s): Same as offline procedure.
Restore Power: Re-apply power to the section from the EPDM. Check that power indicators on the EPDM and EPSM come on, and that green power LEDs on adjacent controller boards come on.
Reconnect Fiber Optics: Reconnect all communication cables.
Reconfigure: After the DSPX is replaced, it must be reconfigured. Refer to the Toolbox software for required procedures.
Functional Test: Verify the replaced DSPX functionality by transferring control from the active master to the inactive master and observing correct system operation.
