DynaVox iChat3, User Manual

Page: 65 / 122

Palmtop3 User’s Guide
Part # 400670-A
53
Three types of encryption can be selected using the Encryption drop-down menu:
• In Normal encryption, all characters except spaces and certain field delimiters are encoded in a
recoverable format.
• Even spaces are encoded with Strong encryption.
• With Perfect encryption, the output data will be encrypted in an unrecoverable manner. Although the
messages recorded under perfect encryption can never be recovered, certain types of logfile
analysis are still possible. For example, the overall communication rate can be computed without
knowing the actual messages.
For Normal and Strong encryption, an encryption key is required. This string of characters is used to initialize
the encryption process. The encryption key is specified in the Key box. The key can be any combination of
letters (lower or uppercase) and numbers. Do not use punctuation marks or other symbols in the key.
Additionally, you can specify a password in the Password box. Without a password, any standards-compliant
analysis program (such as ACQUA) can decrypt an encrypted file (except for those encoded with Perfect
encryption). If a password is specified, however, an analysis program will not be able to decrypt the logfile
without that password.
Warning: If you choose to use a password, make sure that you will remember it. If you forget
the password, the logfile cannot be decrypted.
The remainder of the Logging Setup dialog configures the kind of information will be sent to the logfile.
Select the information fields from the Fields viewport by clicking them (click again to unselect). Many fields
are self-explanatory. For detailed information, consult the logfile standards web page on the DynaVox
website (
www.dynavoxtech.com/about/logfile.aspx or www.dynavoxtech.com/about/logfileappendix.aspx ).
The Method drop-down menu allows you to specify when a communication event is logged.
• If the method is set to Human , only those explicit user-generated events will be recorded. You can
use this setting, for example, to ignore automatic scanning advances.
• If the Method is set to Output , only those events that produce an output will be logged. This can be
useful if you do not want to see intermediate steps in message production, such as navigation
commands.
• If you choose All , every communication event will be recorded in the logfile.
Most logfiles include a timestamp to indicate when a particular communication event occurred. The Time
Method drop-down menu allows you to set Absolute , Elapsed , or Delta timestamps.
• An Absolute timestamp is the time of day.
• An Elapsed timestamp is the amount of time that has elapsed since the logfile was first opened.
• A Delta timestamp is the time elapsed since the last communication event.
You can also choose how specific the timestamp will be. The Lower drop-down menu determines the finest
step of time recorded (from thousandths of a second up to seconds). Conversely, the Upper drop-down
menu sets the coarsest time recorded (from seconds to years). So if the Time Method is set to Absolute , the
Lower menu is set to Tenths and the Upper menu is set to Hours , you might see a timestamp of "8:13:22.4",
which means that the event occurred at 22.4 seconds after 8:13 in the morning.
The Context drop-down menu is only used when the Context field is selected. The Context field includes the
last few words of text in each logfile entry, providing some information about the context at the time of each
communication event. The
Context drop-down menu determines how many words of context are recorded.