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Presentation / operation
ABB Control - AC 31
Page 1-7
1SBC 260400 R1001-b
06.99
3. Operation of the 40 and 50 series central units
3.1. Functional diagram
The 40 and 50 series central units memory is composed of two distinct areas:
- A SRAM memory where the user program and data is loaded.
- A Flash EPROM memory which contains:
- a backup of the user program with the program constants,
- the configuration data,
- and the system program protected against access from the user program.
An incorporated battery, which is available only in the 50 series, also enables the backup of
internal variables.
The user program is a set of universal functions conceived by the constructor to cover all
applications and ensure all the basic PLC functions. It is developed with the AC31GRAF
software. After being translated into instructions understable by the central unit it is loaded in
RUN or STOP mode into the SRAM and then saved from the SRAM to the Flash EPROM.
Thereby, at each program launch the user program, saved in the Flash EPROM, is copied to
the SRAM for processing by the microprocessor (Figure 1-3).
The structure of the system program memory, the user program, the inputs / outputs and
internal variables are described in the annex (mapping).
Summary of Contents for AC 31
Page 1: ...Technical Manual Advant Controller 31 40 50 Series 1SBC 260400 R 1001 b ...
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Page 45: ...Technical specifications Page 3 2 ABB Control AC 31 1SBC 260400 R1001 b 06 99 ...
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Page 85: ...Installation Page 4 2 ABB Control AC 31 1SBC 260400 R1001 b 06 99 ...
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Page 130: ...Programming ABB Control AC 31 Page 5 21 1SBC 260400 R1001 b 06 99 ...
Page 182: ...Communication ABB Control AC 31 Page 7 11 1SBC 260400 R1001 b 06 99 ...
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Page 218: ...AC 31 technical documentation ABB Control AC 31 Index Page 1 1SBC 260400 R1001 b 06 99 Index ...