Specifications

6
Controller Hardware Features
LED Indicators
The DDC is equipped with three sets of LED
banks that help the user diagnose problems
and/or identify normal operation.
The first bank of LEDs is located in the
upper left-hand corner as shown in Figure 2.
The LEDs (Rx and Tx) flash repeatedly
when the controller is communicating with
the network.
The second bank is located on the upper
right hand corner of the controller as shown
in Figure 3. The top LED (POWER) is
normally lit green to indicate that the
controller is powered. The middle LED
(RUN) represents the “heart beat” of the
controller and flashes green during normal
operation. The bottom LED (ERROR) is
usually off during normal operation and only
lights up red when the controller detects an
error. In addition, when downloading new or
modified versions of software these LEDs
will flash on and off, indicating new files are
being written to the controller’s non-volatile
memory.
Figure 2 - Network LEDs
Figure 3 - Power LEDs
Figure 4 – Digital Output LEDs