Chapter Seventeen - DIAGNOSTICS
The U-1496 series modems provide several diagnostic capabilities:
Power-Up Self-Test
Analog Loopback Test
Analog Loopback with Self-Test
Local Digital Loopback Test
Remote Digital Loopback Test
Remote Digital Loopback with Self-Test
Line Condition Status Display
Eye Pattern Display
Re-transmission Indicator
Throughput Display
Link Status Report
Modem Reset
All these capabilities can apply to asynchronous or synchronous, error controlled or non-error
controlled, data compression enabled or disabled data mode. You can use these capabilities to
verify the line condition and the modem's functioning and performance, and to locate the source
of a communication problem.
POWER-ON SELF-TEST
Each time the modem is powered-up or receives the reset command from panel, the modem will
test the ROM code checksum, system RAM memory, DSP code checksum, DSP RAM memory,
EEPROM, digital circuits, and analog circuit calibrations.
On the U-1496 panel, the LCD will display the results of the power-on self-test:
(0)
'SYSTEM TESTING....' Self-test start indicator, if no error occurs, this message will
continue up to the end of the test.
(1)
'ROM TEST FAIL....'
ROM code checksum error.
(2)
'RAM TEST FAIL....'
System RAM fail.
(3)
'XROM CHKSUM ERROR....'
EEPROM checksum error, program will download the
factory default settings to EEPROM and re-initialize the self-test. This is not a real error.
(4)
'DSPA RAM FAIL....'
The testing of DSP A RAM fails.
(5)
'DSPB RAM FAIL....'
The testing of DSP B RAM fails.
(6)
'V0 CALIBRATION FAIL....'
Analog circuit calibration error.
(7)
'VR CALIBRATION FAIL....'
Analog circuit calibration error.
(8)
'FR CALIBRATION FAIL....'
Analog circuit calibration error.
(9)
'DSPA COMM FAIL....' Communications between controller and DSP A fail.
(10)
'DSPB COMM FAIL....' Communications between controller and DSP B fail.
The reset command from the panel will restart the power-on self-test. If an error message is
displayed on the LCD screen, turn off the modem, wait for more than 10 seconds, turn the power
on again. If the modem continues to display an error message, call the ZyXEL Service Center for
assistance, or follow the return procedure to return the modem to ZyXEL. If the normal IDLE
SCREEN shows up, the original failure was due to a temporary power-on reset problem and will
not affect modem operation.
