Siemens SIMATIC S7-300 Series Reference Manual page 173

Code block
A SIMATIC S7 code block contains part of the STEP 7 user program. (In
contrast: ³ data block only contains data.)
Compress
The programming device online function "Compress" is used to align all valid
blocks contiguously in the RAM of the CPU at the start of the user memory. This
eliminates all gaps which arose when blocks were deleted or modified.
Communication processor
Communication processors are modules for point-to-point and bus links.
Configuration
Assignment of modules to racks/slots and (e.g. for signal modules) addresses.
Consistent data
Data whose contents are related and which should not be separated are known
as consistent data.
For example, the values of analog modules must always be handled consistently,
that is the value of an analog module must not be corrupted by reading it out at
two different times.
Counter
Counters are integrated in ³ CPU system memory. The content of the "counter
cells" can by modified by STEP 7 instructions (e.g. count up/down).
CP
³ Communication processor
CPU
Central processing unit of the S7 programmable controller with open and
closed-loop control systems, memory, operating system and interface for
programming device.
PLC S7-300, CPU Specifications CPU 312 IFM to CPU 318-2 DP
A5E00111190-01
Glossary
Glossary-3