User`s manual

System Status LEDs, Continued
Yellow (WARN) LED
Blink Codes
The yellow (WARN) blink codes are shown below. The yellow (WARN)
status LED will light any time a link error is present. That is, any time at
least one red (FAULT) link LED is lit, the yellow status LED will also be lit
(green and red LEDs will be off).
Number of blinks: Error:
1 RAM failure
2 FLASH checksum error
3 Invalid configuration
4 Reserved
5 Other hardware failure during self-test
6 Duplicate IP address detected
7 Cross-link failure
Hub Port LEDs
The Uplink and Downlink ports each have a status LED. The LED for
each port can either indicate red (FAULT) or green (NORMAL).
The green LED is on once the link has become established (active). It
will remain on as long as the link is active (i.e., polls/responses are
received within a timeout period). The green LED will blink off
(~100mSec) for each information-carrying frame sent or received, with a
minimum of 100mSec “on” time between blinks.
Green (NORMAL) LED
When the hub detects an address loop (the same IP address is being
used on multiple hubs), the port is disabled and green LED will remain
off until the user changes the IP addresses and resets the port.
On active links, the hub indicates transient errors by blinking the red LED
briefly (~100mSec). The red LED is on if the link has been active since
the hub was last powered on or reset but has subsequently become
inactive. A link will become inactive if the wires are disconnected,
shorted, or a message is dropped after three retries. If a channel has
never been active since the DNH was last powered-up or reset, both
LEDs will be off. This is intended to reduce spurious error indications for
channels that are completely disconnected.
Red (FAULT) LED
2000585-001 Data Communications Setup • 63