Troubleshooting Terminal, Printer, and Serial Device Connections - Edition 5 (32022-90058)

General Information
Powerfail Recovery
Chapter 1
21
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 2 0minutes. 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.