Siemens SIMATIC S7-1500 Operating Instructions Manual page 100

Glossary
PG/OP communication
Communication between the CPU and other S7 applications, such as programming devices,
operator panels, and S7 controllers. The CPU supports Industrial Ethernet for PG/OP
communication.
PLC
Programmable logic controller - electronic control system. The PLC functions are stored in a
program on the control device. The device configuration and wiring are therefore
independent of the controller functions. The PLC is configured similar to a computer. It
consists of a CPU with memory, input and output devices, and an internal bus system. The
I/O and the programming language are oriented to control engineering requirements.
Priority
The priority of an application determines the order in which the operating system executes or
interrupts an application in relation to the other applications that are running on the
computer. An application with a higher priority interrupts the execution of an application with
a lower priority. After the application with the higher priority finishes, the application with the
lower priority resumes. A higher number indicates a higher priority.
PROFIBUS
Physical communications layer that can be used for PROFIBUS DP communication with I/O
or S7 communication with STEP 7, S7 CPUs, and S7 applications.
PROFIBUS DP
Communications network protocol used to communicate to DP I/O.
PROFINET IO
Communications network protocol used to communicate with PROFINET IO devices.
S7 communication
Communication between controllers on the network, hardware or software, using the S7
communication functions.
Scan cycle
The cycle includes writing to the outputs, reading the inputs, executing OB 1, and satisfying
the idle time requirement.
STEP 7 user program
Application program created with STEP 7 and downloaded to the CPU for execution. It
includes all organization blocks and the other instructions that they call.
100
CPU 1505SP (F) Ready4Linux Version 2.7
Operating Instructions, 05/2019, A5E46864285-AA