Troubleshooting Terminal, Printer and Serial Device Connections - Edition 4 (32022-90030)

20 Chapter 1
General Information
Powerfail Recovery
Powerfail Recovery
DTC powerfail recovery works for direct-connect nailed sessions using
character mode. The system also attempts to recover direct-connect
sessions using block mode; however, this might not be successful if the
powerfail has affected terminal configuration. This is especially true for
VPLUS applications.
In the event of a DTC powerfail, some data loss might occur. Data
buffered in the DTC at the time of the powerfail is not recoverable.
Upon system powerfail, the DTC retains sessions for approximately
20 minutes. This exceeds the duration of battery back-up on the system
(15 minutes). Upon DTC powerfail, the system also retains sessions for
about 20 minutes. If power is not restored before this time, sessions are
aborted.
The terminal appears “hung” for approximately two minutes after
power has been restored to the DTC (the time it takes for the DTC
selftest and download to complete). Once the DTC is downloaded, there
is a 10 second period for powerfail recovery of active sessions. During
this time, the DTC will not respond to user input (pressing carriage
return).
After this time, device control is restored. No “powerfail occurred”
message is displayed. To confirm that device control has been restored,
press
[Return] until the colon prompt (:) is displayed.
In the event of a DTC powerfail, printer and modem connections as well
as connections created via PAD and Telnet/iX are aborted.