Siemens SIMATIC S7-1500 System Manual page 377

PROFINET IO controller
Device used to address connected I/O devices (for example distributed I/O systems). This
means that: The IO controller exchanges input and output signals with assigned IO devices.
Often, the IO controller is the CPU on which the automation program runs.
PROFINET IO device
Distributed field device that can be assigned to one or more IO controllers (for example
distributed I/O system, valve terminals, frequency converters, switches).
Reference potential
Potential from which the voltages of the circuits involved are observed and/or measured.
Restart
During a warm restart, all non-retentive bit memory is deleted and non-retentive DB contents
are reset to the initial values from load memory. Retentive bit memory and retentive DB
contents are retained. Program execution begins at the call of the first startup OB.
Retentivity
A memory area whose content is retained after power failure and after a STOP to RUN
transition is retentive. The non-retentive area of the bit memory, timers and counters is reset
after power failure and after a STOP to RUN transition.
RT, real-time
A transmission method for the cyclic exchange of I/O data between PROFINET devices. The
transmission method guarantees that the I/O data is transferred at deterministic intervals.
Runtime error
Error that occurs during execution of the user program in the automation system (thus not in
the process).
SELV
Safety Extra Low Voltage = Safety extra-low voltage
Sensor Module
Component for implementing encoder interfaces on DRIVE-CLiQ.
SIMATIC Drive Controller
The SIMATIC Drive Controller is a drive-based controller in the SIMATIC S7-1500 range.
SIMATIC Drive Controller
System Manual, 11/2023, A5E46600094-AD
Glossary
375