Comtrol VS3000S - Manual (Page 19)

Installing the VS3000 19
Installing the Hardware
6. Turn the VS3000 power switch to the on (1) position and watch the
LED lights (on the back/front of the VS3000) for the following
activity during the self-diagnostic power up sequence.
a. All of the LEDs flash on for one second and then off, to indicate
that the LEDs work.
b. If using a 10Base-T Ethernet connection, the lower LED
remains lit to indicate that you have link polarity on the
connection.
Note: Check the link polarity at the hub to make sure that there is
Ethernet polarity at both ends of the Ethernet cable.
If the lower LED is off, then the unit is not connected to a LAN
system or it is connected by the AUI port. If using an AUI
connection to the server, you can determine whether the line is
working by using an AUI to 10Base-T convertor box.
c. The D channel LEDs flash in sequence from port to port during
a test of ISDN components and verification of the ISDN lines.
This takes about 30 seconds.
d. All of the LEDs turn off for a moment.
Note: If all of the LED lights on any particular port flash on and
off several times in sequence (B1, B2, and D) before the next
step, there may be a problem with the ISDN line or the
hardware for that port. It indicates that the ISDN
hardware could not synchronize with the central office
(CO).
e. The B1 LED on PORT 1 flashes to indicate that it is waiting for
a control program (VS-Link) to download.