Technical data

Glossary
System Software for S7-300/400 System and Standard Functions - Volume 2/2
Glossary-14 A5E00739858-01
Statement List
The Statement List is the assembly language of STEP 7. When a program is
processed in STL, the individual instructions correspond to the sequence with
which the CPU processes the program.
STEP 7
Programming software for creating user programs for SIMATIC S7 controllers.
STEP 7 Programming Language
Programming language for SIMATIC S7 controllers. The S7 programmer can use
STEP 7 in different representation types: a) Statement List, b) Control System
Flowchart, c) Ladder Logic.
Step Controller
A step controller is a quasi continuous controller with a discontinuous output (and
motor-driven actuator with an I action). The actuator has a three-step response, for
example, up - stop - down (or open - hold – close).
(Three-step controller).
STL
Statement List.
Subnumber
The number of the signal to be monitored if a message block can monitor more
than one signal.
Symbol-Related Message
A message used in configuring messages for a symbol (input, output, bit memory,
data block) in the symbol table. During configuration, the time interval must be set
for the SCAN function used to monitor the signal.
Symbolic Programming
The STEP 7 programming language allows the use of symbolic names instead of
STEP 7 addresses. For example, a STEP 7 address "Q 1.1" can be replaced with
"Valve 17."
The symbol list in STEP 7 also creates the link between the address and the
assigned symbolic name.
System Diagnostics
The detection and evaluation of system diagnostic events.