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Primarily, the extended memory is divided onto 19 free-programmable memory
partitions:
- one event logging partition
- 16 data logging partitions
- one partition for high-speed waveform logging (32 points × 16 cycles)
- one partition for high-resolution waveform logging (128 points × 4 cycles)
Each partition is dedicated to a specific data format and occupies continuous block
of memory space. The size of each partition can be configured from zero and up to
the entire memory size, allowing the user to best utilize the available memory for
different applications. Existing memory partition may not be directly resized. If a
partition need to be changed, it must be deleted and then allocated again with the
desired size and properties. At any time, the user can delete unused partitions in
order to expand the amount of memory to use by other partitions, and restore a
deleted partition when he needs it.
NOTE
Although any partition can be easily deleted, it is not recommended to completely delete
the event log partition, because in this case the instrument will have no possibility to record
events regarding its operation and security.
Location of each partition in the memory module does not depend on its order in a
list of partitions. Each time the user reconfigures the extended memory, the
instrument performs memory optimization to keep free memory space in one
continuous block, by moving the existing partitions onto lower addresses. Due to
this technique, all free memory is always available for the user needs. Note that
while optimizing the memory, the instrument will not respond to incoming
communications requests. In the worst case, it can take up to 1 second per 128K
byte of memory.
For each partition, the user can select one of two modes of behavior when a partition
is filled up: wrap-around, or non-wrap. For a non-wrap partition, recording stops
when the last record is written to the partition, so that a partition keeps the oldest
records without overwriting previously recorded data. When the user wants to
restore recording, he need clear the partition. For a wrap-around partition, recording
continues over the oldest records without pause, so that the partition will always
keep the most recent data, although old records might be lost.
Recorded data is always read in turn, in the same sequence that they were written.
Each partition uses a dedicated pointer that points to the following available record.
After the record is read, the pointer is shifted forward to the next record until the last
78
Operation Techniques
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