Monitoring LEDs

8-3

Monitoring the D Channel LED

Observe the D channel LED. If you are connected to a live digital ISDN line, the D channel LED remains lit for a few minutes after the self-test and then begins to flash. When the D channel LED flashes, it indicates that the ISDN signal is present and it is attempting to synchronize with the telephone company.

When the D channel LED goes out, it indicates that a valid communication channel has been established and you can place calls. If the D channel LED does not go out, refer to the “Evaluating Symptoms and Solutions” section.

Monitoring the B Channel LEDs

Attempt to place a call and observe the B channel LED(s). The B1 and B2 LEDs flash amber for a voice call or green for a data call during the call establishment phase. They then remain continuously amber or green once the connection is established. If they do not remain continuously amber or green, refer to the “Evaluating Symptoms and Solutions” section below.

Monitoring the SD LED

When flashing, the Send Data LED indicates that information is being transmitted over the serial data port from the computer to the 3C882 ISDN Modem.

If this LED flashes and yet you are not able to communicate with the ISDN modem, you may be attempting to communicate at incompatible baud rates. Refer to “Restoring the 3C882 ISDN Modem to Autobaud” below.

Monitoring the RD LED

When flashing, the Receive Data LED indicates that information is being transmitted over the serial data port to the computer from the 3C882 ISDN modem.

If this LED flashes and yet you are not able to communicate with the 3C882 ISDN modem, you may be attempting to