Omega Engineering OMB-CHARTSCAN 1400, User Manual

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Configuration Aspects for Programmers Appendix B
B-2 ChartScan User’s Manual
Memory Allocation
Each ChartScan comes equipped with 256 KB memory. There are three options for additional memory:
1 Mbyte, 4 Mbytes, and 8 Mbytes. The memory modules are located in SIMM sockets JP201 and/or JP202 on
the microprocessor board. Refer to Chapter 3 if you intend to add or remove memory modules.
Regardless of the memory option used, ChartScan will automatically allocate its memory for optimal use
according to its current configuration. ChartScan memory is broken into two main regions, as shown in the
following figure.
• High/Low/Last Data Registers (only configured channels)
•
Acquisition Data Buffer
When channels are configured, ChartScan will calculate how
much memory will be needed for the High/Low/Last
Registers. The memory allocated to High/Low/Last is:
• (Number of channels) x 20
The remaining memory is then allocated to the Acquisition
Buffer. For example, if the memory option used is the
standard 256K (262144 bytes) and the number of configured
channels is 128 (x 20) then the amount allocated to the
acquisition buffer would be:
262144 Total Memory Option Size (256K)
- 19840 High/Low/Last Data Size (128 x 20)
242304 Acquisition Data Buffer Allocation (236.6K)
ChartScan Memory Allocation