GFK-2571A
Chapter 5 Diagnostics
5-5
5
Special LED Blink Patterns
In addition to the LED blink patterns that indicate a fatal error, the PNC
’s LEDs can indicate module
location/identification and microprocessor overtemperature conditions, as described below.
Special LED Patterns - Module Identification
The LEDs on a PNC module can be commanded to repeatedly turn ON and OFF in a special
sequence, to help locate or identify the module:
First the LEDs are turned on in the following order: OK, LAN, STATUS, CONFIG, PORT 4,
PORT 3, PORT 2, PORT 1. There is a short delay between turning on each LED.
The LEDs are then turned off in the same order. There is a short time delay between
turning off each LED.
The command,
blinkId
<begin/end> is issued via the Command Line Interface. Issuing the
blinkId
begin
command starts the identification blink sequencing while the
blinkId end
stops the
identification blink sequencing. When issued from the Command Line Interface, the last command
session that commands the IDENTIFICATION blink pattern determines its state (either blinking or
stopped). Note that the
blinkId
command requires Modify-level access to the Command Line
Interface.
Special LED Patterns - Microprocessor Overtemperature
If the maximum threshold temperature for the PNC
’s microprocessor is crossed, the PNC goes into
power-saving mode. While the PNC is in an overtemperature condition, LEDs on the module flash at
half-second intervals:
OK green
LAN green
STATUS green
CONFIG amber,
ACTIVE green, USB red
P1 and P2 green
The PNC stays in power-saving mode until the temperature drops to a safer level. Once a safe
temperature is reached, the PNC module restarts. When the PNC is restarted, it retains any entries
in its Local Log table and its non-volatile configuration parameters. Any debug data in non-volatile
storage can be viewed from the Command Line Interface using the
log
or
show log
command.
Note:
Under certain ambient operating temperatures, the PNC may momentarily display
the overtemperature pattern during power up, while it is calibrating its thermal
protection functions. This indication may be ignored, and no overtemperature entry
is added to the Local Log table, the Controller Fault table or I/O Fault table.