CTI Products NCB/EM with External PSTN Modem - Manual (Page 50)

CTI Products, Inc. NCB-EM User Guide
Appendix E. Troubleshooting 44
Table E4
If the CD LED . . . REASON CORRECTIVE ACTION
Illuminates within 45 seconds
of resetting (“OH” LED is
already illuminated) when
using a Leased-Line.
Normal operation indicating the modem is
connected to another NCB’s modem.
Go to next Table.
Illuminates within 45 seconds
of illumination of “OH”
LED on originating NCB
when using a Dial-Up
line.
Normal operation indicating the modem is
connected to another NCB’s modem.
Go to next Table.
Does not illuminate within 45
seconds of resetting when
using a Leased-Line.
1. Modem switches are not set correctly.
2. Incorrect modem connector.
3. Incorrect 4-wire Leased-Line
connections.
4. Leased-Line is not operating, or faulty
back-to-back cable.
5. Defective modem.
1a. Verify modem Switch 5 is down for
the originating NCB, and up for the
answering NCB.
b. Verify Modem Switch 3 is down (-
9dBm transmit level) for normal
operation, or up (-15 dBm transmit
level) for back-to-back operation (on
both modems)
2. Use ‘LEASED’ or ‘PRIVATE’
connector on rear of modem.
3. See “”.
4. Contact Leased-Line provider for line
status, or replace back-to-back cable.
5. Call CTI Products, Customer Support
(+1-513-595-5900), to arrange to
return unit for evaluation/repair.
Does not illuminate within 45
seconds of illumination of
“OH” LED on originating
modem when using a
Dial-Up Line.
1. Incorrect dial string is being used by
originating NCB. (While initiating a
dial-up connection, and with a handset
connected to the AUDIO connector of
the originating NCB, the dial tone,
followed by the dial sequence, followed
by the repeating busy signal, can be
heard.)
2. Dial-up line is not operating from the
telco switching equipment to the
answering NCB. (While initiating a dial-
up connection, and with a handset
connected to the AUDIO connector of
the originating NCB, the dial tone,
followed by the dial sequence, followed
by the repeating ringing signal, can be
heard.)
3. Incompatible modems.
4. Defective modem.
1. Verify dial string.
2. Contact Dial-up line provider for line
status.
3. Verify that modems are compatible
with each other.
4. Call CTI Products, Customer Support
(+1-513-595-5900), to arrange to
return unit for evaluation/repair.