Firmware - GE D20 Technical Overview

GE Grid Solutions
2.4.3.1 Status Indicators
All D20 I/O Modules are equipped with the following LEDs:
LED
ON (GREEN)
RUN (GREEN)
TX1 (GREEN)
RX1 (GREEN)
TX2 (GREEN)
RX2 (GREEN)
FAULT (RED)
In addition to the above, each D20 I/O Module is equipped with module-specific status
indicators.

2.4.4 Firmware

There are two main types of peripheral I/O software: common code and base-application code.
Similar to the D20 main processor software, peripheral software is installed as firmware on the
modules. Common code is resident in the peripheral modules, and device-specific base
applications are stored in the D20 main processor then downloaded to the peripheral modules at
boot-up.
2.4.4.1 Common Code
Common-code firmware in the peripheral modules is much like the BootROM firmware in the
D20 main processor. The common code manages functions common to all peripheral units,
specifically the input and output through communications and diagnostic ports. It also performs
diagnostic checks of peripheral hardware.
Common code, which is stored in a 32K EPROM (labeled "pcommon"), remains active after a
restart, whether or not the base-application code has been downloaded to the peripheral unit. This
allows the peripheral unit to communicate and respond to D20/D200 requests, even without its
device-specific base-application code loaded. However, peripheral module responses have an
abbreviated format unless the application code is loaded.
The common code includes the following processes:
• Real-time executive
• Watchdog and reset code
• Diagnostics
• Device drivers
• Communications
• Common code interface
• Maintenance facility and monitor
• Library resources.
GE Information
On solid when power is applied.
With the FAULT LED, provides information about the unit's operating status.
Flashes when D.20 1 data is transmitted by the I/O module.
Flashes when D.20 1 data data is received by the I/O module.
Flashes when D.20 2 data is transmitted by the I/O module.
Flashes when D.20 2 data data is received by the I/O module.
With the RUN LED, provides information about the unit's operating status.
D20/D200 Technical Overview
Description
PRPI-019-3.00-10
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