Siemens S7-400 Installation Manual page 293

Glossary
A
Accumulator (ACCU)
The accumulators are registers in the CPU and are a buffer for load, transfer and
comparison, math and conversion instructions.
Address
An address is the identifier for a specific area of memory on which an instruction
acts.
Examples: Input I 12.1; Memory Word MW24; Data Block DB3.
Analog Module
Analog modules convert analog process variables (for example, temperature) into
digital values that can be processed in the CPU or they convert digital values into
analog manipulated variables.
Application Module
Application modules are function modules from the M7 range.
AT Adapter Module
The ATM 478 AT adapter module provides a slot for a short AT card.
B
Backup Battery
The backup battery ensures that the user program in the CPU is not lost in the
event of a power failure and that defined data areas, bit memory, timers, and
counters are also retained.
S7-400 and M7-400 Programmable Controllers Hardware and Installation
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