Configuration Aspects for Programmers Appendix C
C-2 NetScan User’s Manual
Memory Allocation
Each NetScan 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, NetScan will automatically allocate its memory for optimal use
according to its current configuration. NetScan 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, NetScan 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)