Section 8.  Operation 
 
 
A second instance of a setting can be configured using the same node PakBus 
address and same file type, in which case two files will be written according to 
each of the two settings.  For example, 
(55,USR:photo.JPG,100) 
(55:USR:NewestPhoto.JPG,0) 
will store two files each time a JPG file is received from node 55.    They will be 
named USR:photonnn.JPG and USR:NewestPhoto.JPG.    This feature is used 
when a number of files are to be retained, but a copy of one file whose name 
never changes is also needed.    The second instance of the file can also be 
serialized and used when a number of files are to be saved to different drives. 
Entering 3212 as the PakBus address activates storing IP trace information to a 
file.    The "number of files" parameter specifies the size of the file.    The file is a 
ring file, so the newest tracing is kept.    The boundary between newest and oldest 
is found by looking at the time stamps of the tracing.    Logged information may 
be out of sequence. 
Example: 
(3212, USR:IPTrace.txt, 5000) 
This syntax will create a file on the USR: drive called IPTrace.txt that will grow 
to approximately 5 KB in size, and then new data will begin overwriting old data. 
 
8.8.4.3  Data Preservation 
Associated with file attributes is the option to preserve data in CR800 memory 
when a program is sent. This option applies to final-storage data SRAM, memory 
cards, and datalogger support software 
(p. 86) cache data (p. 494). Depending on the 
application, retention of data files when a program is downloaded may be 
desirable. When sending a program to the CR800 with datalogger support 
software Send command, data are always deleted before the program runs. When 
the program is sent using support software File Control Send
 (p. 498) command or 
CRBasic Editor Compile, Save and Send 
(p. 494) command, options to preserve 
(not erase) or not preserve (erase) data are presented. The logic in the following 
example summarizes the disposition of CR800 data depending on the data 
preservation option selected. 
 
 
if "Preserve data if no table changed" 
 if current program = overwritten program 
 keep CPU data 
 keep cache data 
 erase CPU data 
 erase cache data 
 end if 
if "erase data" 
 
 erase CPU data 
 erase cache data