GE IC754VGI06SKD, Руководство пользователя

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D e t a i l e d O p e r a t i o n
Memory
52
6" QuickPanel View Keypad GFK-2357A
3
M E M O R Y
The QuickPanel View Keypad supports a variety of memory subsystems to ensure
the requirements of your application are met. All system memory is tied directly to
the microprocessor’s address and data busses for fastest access. To increase DRAM
by up to 64 MB, a 100-pin DIMM memory expansion slot is also included.
F l a s h M e m o r y
This block of non-volatile memory (32MB) is the main long-term program storage
for the QuickPanel View Keypad, operating like a virtual hard drive from the point
of view of Windows CE. It is divided into two areas, of which only one is
accessible from Windows CE Explorer. The
Flash Storage folder represents a
block of memory (16MB) available for long-term storage of user application
programs. Another 16MB block is used to store the Windows CE operating system,
and is not directly accessible from Windows CE Explorer.
The operating system and all user application programs are transferred from Flash
to DRAM for execution. Any user additions to the
Windows folder are retained
in Flash Storage when the Backup utility is run.
FLASH memory has a limited write-cycle lifetime. That is, the physical memory
devices wear out after approximately 100,000 cycles (minimum), so it is advisable
to limit file operations such as copy, delete, etc.
The write cycle is much slower for FLASH than it is for other portions of RAM,
therefore FLASH is not recommended for the storage of program variables, or any
data items whose values are dynamic.
Flash memory can optionally be added with a CF Card, which will appear as the
PCFlash Storage folder.
Caution: Do not remove power while the system is writing to the CF card, such as
when copying a Proficy Machine Edition project. Removing power while writing
may lead to data loss and file or CF card corruption. To ensure the system
completes writing to flash and closes all files, see “Shutdown” on page 4.
To add Fla sh memory with a CF C ard
1. Insert a Compact Flash card into CF Port (see page 44). The unit immediately reads the new secondary storage. If
the disk requires formatting, you will be prompted to do so.
2. New memory appears in Windows CE Explorer as
PCFlash Storage
.
External flash memory devices are named after their types of connection and order
of attachment. For example, if you connect two flash memory devices, one via the
CF port and one via the fieldbus connector, the first device connected is named