Glossary - Siemens SIMATIC S7-300 Manual

Glossary

Activation/deactivation of slaves
You activate a DP slave with the SFC 12 "D_ACT_DP" and therefore include it in the cyclic
processing. Deactivating a slave removes the DP slave from the cyclic processing.
Address
An address represents the identifier of a specific address or address range. Examples: input
I 12.1; flag word MW 25; data block DB 3.
Analog module
Analog modules convert analog process values (for example, temperature) into digital values
that can be processed by the CPU, or convert digital values into analog manipulated
variables.
Back-up memory
The backup memory ensures buffering of the memory areas of a CPU without backup
battery. It backs up a configurable number of timers, counters, flags and data bytes, the
retentive timers, counters, flags and data bytes.
Clock flag
Flag which can be used to generate clock pulses in the user program (1 flag byte).
Note
When operating with S7300 CPUs, make sure that the clock flag byte is not overwritten in
the user program!
Code block
A SIMATIC S7 code block contains elements of the STEP 7 user program. (In contrast to a
data block: This contains only data.)
S7-300 CPU Data: CPU 315T-2 DP
Manual, 12/2005, A5E00427933-02
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