Specifications

PERFORMING DOWNLOADS
Omni 37xx Download Differences
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MNI 37XX REFERENCE MANUAL 97
terminal, the application executes and the application prompt or logo displays
on the terminal.
Timing Considerations Due to the Authentication Process
The file authentication process takes some time. The total amount of time
required depends on a number of factors:
• the number and size of application files
• the number of certificates and signature files
• whether the file compression feature of Download Manager is being used to
perform the download
Here are a few additional considerations that may affect the total elapsed time
required to complete the download operation:
• Because additional processing steps are required, an operating system
download takes longer to complete than an application download (several
minutes as opposed to a few seconds).
• The download order of a batch of certificate files may affect total processing
time. Digital certificates are validated in a looping process where the validation
process cycles as many times as necessary to establish the proper
relationship and position of a given certificate in the certificate tree that exists
in the terminal.
To optimize the authentication process, you can download certificates in a
higher-level-certificates-first order. This way, they process faster than a
random order download.
Optimize Available Memory Space for Successful Downloads
One certificate file or signature file requires approximately 400 bytes of memory
space. The application designer must account for the extra memory required to
download and store these special files.
When planning your download procedure, carefully consider the total amount of
memory space required to store certificates and signature files
and the application
files. In some cases, a considerable number of 400-byte signature files reside in
terminal memory at any given time. Here are some general guidelines to follow:
• Know the size of available memory (RAM and flash) of the receiving terminal;
in back-to-back downloads, memory on both the sending and receiving
terminal.
• Know in advance how application files are redirected to RAM or flash and to
file groups other than the target group.
• Defragment flash memory before performing a download to optimize the
available space in the flash file system.