Programming manual M238 | 3 MB - BERGER - POSITEC
Programming manual M238 | 3 MB - BERGER - POSITEC
Programming manual M238 | 3 MB - BERGER - POSITEC
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Memory Mapping<br />
Memory Organization<br />
Introduction<br />
This section describes the RAM (Random Access Memory) size for different areas<br />
of the Modicon <strong>M238</strong> Logic Controller.<br />
T<strong>M238</strong>LFDC24DT and T<strong>M238</strong>LFAC24DR Memory<br />
The RAM size is 2 Mbytes composed of 2 areas:<br />
1048 kbytes System Area for Operating System memory<br />
1000 kbytes Customer Area for dedicated application memory<br />
Memory containing Persistent and Retain variables is preserved and protected by<br />
an external battery during power outages.<br />
This table shows the different types of memory areas with their sizes in the<br />
T<strong>M238</strong>LFDC24DT and T<strong>M238</strong>LFAC24DR memory:<br />
Area Element Size (bytes)<br />
System Area<br />
1048 kbytes<br />
System Area Mappable Addresses<br />
%MW0...%MW59999<br />
System and Diagnostic variables<br />
(%MW60000...%MW60199)<br />
This memory is accessible through ModBus<br />
requests only.<br />
These must be read-only requests.<br />
Dynamic Memory Area: Read Relocation Table<br />
(see page 28)<br />
(%MW60200...%MW61999)<br />
This memory is accessible through ModBus<br />
requests only.<br />
These must be read-only requests.<br />
120000<br />
24 EIO0000000384 04/2012<br />
400<br />
3600<br />
Reserved 400<br />
Dynamic Memory Area: Write Relocation Table 3600<br />
(see page 28)<br />
(%MW62200...%MW63999)<br />
This memory is accessible through ModBus<br />
requests only.<br />
These can be read or write requests.<br />
Reserved 945152<br />
(1) Size checked at build time and must not exceed the value indicated in the table.
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