GE WESDAC D20M++ Processor Control Module

The GE Fanuc WESDAC D20M++, also cataloged as the D20M++ Control Module, operates as a central processing unit for data concentration, protocol translation, and real-time automation logic execution within VMEbus-based industrial automation platforms.

Hardware Specifications

GE Fanuc Industrial Control and Backplane Execution

• Backplane Bus Communication Velocity Licences: The module locks directly into standard parallel VMEbus backplane systems, mapping its local memory registers to the master address space. It executes data word synchronization, peripheral polling loops, and interrupt processing sequences within deterministic sub-millisecond bus cycle intervals.
• Firmware Flash Compatibility: The module incorporates high-density non-volatile ROM cells that house the system's core operating environment and driver packages. This memory architecture secures the control system parameters and communication configuration tables against accidental deletion or sudden power failure, discarding the need for physical memory-retention batteries.

Frequently Asked Questions

Q: Can the WESDAC D20M++ module be extracted from the VME rack while the system backplane power is active?

A: No. Standard VMEbus specifications do not permit live hot-swapping of the primary processing units. Attempting to pull or insert the module while the +5 VDC rack power rail is energized can cause pin-level data arcing, corrupt register tables on adjacent cards, or induce a total backplane communications lockup.

Q: What technical indicators confirm a system memory fault during the initialization sequence?

A: During the power-on self-test (POST) routine, the microprocessor runs parity and checksum calculations against the integrated ROM and RAM sectors. If a corrupted memory bit is encountered, the module drops out of the boot sequence, logs a memory exception to the diagnostic register, and changes the front-panel status indicators to a fault pattern.