Siemens Simatic S7-1500/ET 200MP, Системное руководство

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Glossary
Automation system
System Manual, 12/2017, A5E03461182-AE
347
NTP
The Network Time Protocol (NTP) is a standard for synchronizing clocks in automation
systems via Industrial Ethernet. NTP uses the UDP connectionless network protocol.
Organization block
Organization blocks (OBs) form the interface between the operating system of the CPU and
the user program. The organization blocks determine the order in which the user program is
executed.
Parameter
● Tag of a STEP 7 code block:
● Tag for setting the behavior of a module (one or more per module). In as-delivered state,
every module has an appropriate basic setting, which you can change by configuring in
STEP 7. There are static and dynamic parameters
Parameter assignment
Parameter assignment is the transfer of parameters from the IO controller / DP master to the
IO device / DP slave.
Parameters, dynamic
In contrast to static parameters, you can change dynamic parameters of modules during
operation by calling an SFC in the user program, e.g. limit values of an analog input module.
Parameters, static
In contrast to dynamic parameters, you cannot change static parameters of modules with the
user program but only by configuring in STEP 7, e.g. input delay of a digital input module.
PELV
Protective Extra Low Voltage = grounded extra low voltage with safe isolation
Pre-wiring
Wiring of the electrical system on the front connector before the front connector is used on
the I/O module.
Process image (I/O)
The CPU transfers the values from the input and output modules to this memory area. At the
start of the cyclic program the signal states of the input modules are transmitted to the
process image of the inputs. At the end of the cyclic program the process image of the
outputs is transmitted as signal state to the output modules.