GE IS200DSPXH1CAA Digital Signal Processor Control Board

The IS200DSPXH1CAA is a Digital Signal Processor Control Board (DSPX) manufactured by GE Energy as part of the EX2100™ Excitation Control and Innovation Series™ drive families. This board serves as the primary controller for bridge and motor regulator and gating functions in Innovation Series drives, and also controls generator field control functions for the EX2100 Excitation Control. The DSPX board provides comprehensive logic, processing, and interface functions essential for reliable operation of industrial drive and excitation systems.

The IS200DSPXH1CAA is a high‑performance board built around a 60 MHz digital signal processor (DSP) with extensive memory resources and custom logic implemented in an ASIC (Application Specific Integrated Circuit). The board includes Flash memory for boot images and code execution, RAM for data storage, NVRAM for nonvolatile data, and an add‑only memory for board revision identification. The board is designed for VME type rack mounting and connects to the system backplane through a 4‑row, 128‑pin DIN connector (P1). In EX2100 applications, the DSPX board is physically attached to the EISB (Exciter ISBus Board) underneath it; these two boards can be detached if required.

The suffix CAA indicates a specific revision and factory configuration (including conformal coating and component selection) that maintains full backward compatibility with all EX2100 and Innovation Series systems while incorporating the latest design enhancements. The board features two front‑panel LEDs for visual status indication and three I/O connectors: the P1 backplane connector, the P5 DSP emulator port, and the P6 engineering monitor port.

Functional Description

The IS200DSPXH1CAA is the central processing unit for the bridge and motor regulator functions in Innovation Series drives and for generator field control in EX2100 excitation systems. The board's 60 MHz DSP executes control algorithms, processes feedback signals, and generates gating commands for power semiconductor devices (IGBTs or SCRs).

Processor and Memory

The Digital Signal Processor runs at 60 MHz and supports four external interrupts during normal operation:

• Stack overflow (INT0)

• Inner loop load pulse (INT1)

• Two configurable inputs (INT2, INT3)

The board is equipped with the following memory types:

• Flash memory – for DSP boot images, code execution, configurable item storage, and system history records

• RAM – for data storage and code execution

• NVRAM – for nonvolatile data storage

• Add‑only memory – for board revision identification

Specialized Hardware Functions

Custom logic functions are implemented in a single ASIC with supporting circuits. Key specialized functions include:

• Serial Interfaces – Four serial interfaces to the backplane: two 5 Mb/s ISBus™ interfaces (master or slave), one asynchronous TTL interface for a PC‑based configuration tool (RX, TX, TXEN/RTS), and one asynchronous TTL interface to a programmer board (RX, TX, RTS).

• Synchronizing Load Pulse Signals – An inner loop load pulse captures I/O values (voltages, currents, tachometer counters, discrete inputs) and synchronizes ISBus channels, software, and gating outputs. An application loop load pulse captures other application VCO values at sub‑multiples or multiples of the inner loop.

• Stack Overflow Detection – Monitors both foreground and background stacks; generates INT0 if either overflows, and a hard reset if both overflow. A configuration register allows the reset to be disabled.

• Watchdog Timer – Enabled and periodically toggled by the DSP; a timeout generates a hard reset. A 24‑bit free‑running timer is also provided as a reference for certain functions.

• Differential Inputs (HIFI) – Five differential pairs can be used as two quadrature incremental tach interfaces (one with marker capability), as application layer VCO counters, or as up to ten discrete inputs. Associated 16‑bit up/down counters, timers, and capture registers are provided.

• VCO Inputs – Six bridge VCO inputs (0–2 MHz) from technology‑specific I/O cards (e.g., BIC bridge interface cards) are digitally filtered and fed to 16‑bit counters with capture registers latched by the inner loop load pulse.

• PWM Outputs – Two fixed‑frequency (24 kHz) PWM outputs with 10‑bit resolution for driving instrumentation meters or other outputs.

• Miscellaneous I/O – SYNC OUT for synchronizing functions at the BIC board layer, a BIC_DISABLE output (high disables BIC board during power‑up), and various clock, interrupt, and chip select signals.

Onboard Firmware

The onboard firmware is stored in Flash memory and consists of three main types:

• Boot loader – controls the power‑up sequence and should not be reloaded in the field

• Application code – defines specific control functions for the drive or exciter product; loaded through the Tool port

• Configuration parameters – loaded using the ToolboxST software; exciter parameters are loaded over the Unit Data Highway, while drive parameters are loaded through a serial port, ISBus, or Ethernet to the ACL board

Indicating Lights

The board includes two front‑panel LEDs for visual status indication:

Hardware Characteristics

Physical Form Factor and Mounting

The IS200DSPXH1CAA is a printed wiring board designed for VME type rack mounting. It connects to the backplane through a 4‑row, 128‑pin DIN connector (P1). In EX2100 applications, the DSPX is attached to an EISB board underneath it; these two boards can be detached if required. The board has no fuses, adjustable hardware devices, or user testpoints.

Connectors

I/O Signal Summary (P1 Backplane)

Installation and Replacement

Handling Precautions

• Static sensitivity – The IS200DSPXH1CAA contains static‑sensitive components. Always wear a wrist grounding strap and handle the board at a grounded workstation. Store the board in its antistatic bag when not in use.

• De‑energise before handling – Turn off power to the drive or exciter and verify zero voltage before touching the board or any connected circuits. Follow lock‑out/tag‑out procedures.

• Do not insert or remove with power applied – Doing so may cause equipment damage or personal injury.

Replacement Procedure (Innovation Series Drives)

1. De‑energise the drive and open the cabinet door. Test for zero voltage on all circuits.

2. Loosen the top and bottom captive screws near the ejector tabs.

3. Raise the ejector tabs to unseat the board, and pull it straight out.

4. Slide the replacement board into the correct slot (boards are keyed; inserting into the wrong slot can damage electronics).

5. Press firmly on the top and bottom of the front panel simultaneously to seat the board.

6. Tighten the screws evenly to ensure proper seating.

Replacement Procedure (EX2100 Offline)

1. De‑energise the exciter following GEH‑6631 or GEH‑6674 procedures.

2. Disconnect the six fiber‑optic cables from the EISB front panel.

3. Remove the DSPX and attached EISB as a unit using ejector tabs.

4. Detach the EISB from the old DSPX and attach it to the replacement IS200DSPXH1CAA.

5. Install the replacement assembly and reconnect all cables.

6. After replacement, reconfigure the DSPX using the ToolboxST software.

Replacement Procedure (EX2100 Redundant Online)

1. Identify the failed DSPX using front‑panel LEDs.

2. De‑energise only the section (M1, M2, or C) containing the failed board.

3. Confirm control has transferred to the other master.

4. Disconnect fiber‑optic cables and remove the DSPX/EISB assembly.

5. Install the replacement assembly and restore power.

6. Test the replacement by transferring control to it.

Ordering Information

When ordering the IS200DSPXH1CAA, use the complete part number exactly as shown. The part number follows GE’s convention:

• IS200 – Innovation Series, 200‑class

• DSPX – Functional acronym: Digital Signal Processor Control Board

• H1 – Generation/version

• C – Base designator

• A – Modifier (e.g., coating or component variation)

• A – Revision A

Warranty and Order Placement

• Warranty replacements (within warranty period): Contact GE Energy Product Service Engineering (contact details omitted per request).

• Spare parts or non‑warranty orders: Contact your nearest GE Sales or Service Office. Provide:

  • Complete part number: IS200DSPXH1CAA

  • Drive or exciter serial number

  • Drive or Exciter Material List (ML) number

Note: All digits and letters in the part number are significant. GE may substitute later compatible revisions, but backward compatibility is assured.

Diagnostics and Maintenance

The IS200DSPXH1CAA does not require routine calibration. Its health is monitored by the control system via the FAULT and STATUS LEDs and through diagnostic alarms reported by the ToolboxST software. The board performs continuous self‑diagnostics including:

• Stack overflow detection (foreground and background)

• Watchdog timer monitoring

• Memory integrity checks

• Communication link status with ISBus and other interfaces

If the FAULT LED is ON or flashing, a fault has occurred. If the STATUS LED is OFF, a fault has occurred or the board is in reset. When the board is running normally, the STATUS LED should be flashing green.