Siemens SIMATIC S7-1500 System Manual page 369

Cross-PLC synchronous operation
This functionality allows you to create a master value source and a synchronous axis on
different controllers.
Cycle control point
The cycle control point marks the end of a cycle and the start of the next cycle. The cycle time
statistics and monitoring of the configured maximum cycle time start at the cycle control
point.
Once the cycle control point has been reached, the CPU writes the process image output to
the output modules, reads the state of the inputs in the input modules and then executes the
first cyclic OB.
Cycle time
The cycle time represents the time a CPU requires to execute the user program once.
Cyclic interrupt
You can find relevant information in the entry "Interrupt, cyclic".
Data block
Data blocks (DBs) are data areas in the user program that contain user data. There are global
data blocks, which can be accessed from all code blocks, and instance data blocks, which are
assigned to a specific FB call.
Device
A device can send, receive or amplify data via the bus, e.g. IO device via PROFINET IO.
Device names
Before an IO device can be addressed by an IO controller, it must have a device name. This
approach was chosen for PROFINET because names are easier to administer than complex IP
addresses.
In its delivery state, an IO device has no device name. An IO device can only be addressed by
an IO controller – for example for transferring configuration data (including the IP address)
during startup, or for user data exchange during cyclic operation – after it has been assigned
a device name with the PG/PC.
Diagnostic buffer
The diagnostic buffer is a battery-backed memory area in the CPU where diagnostic events
are stored in their order of occurrence.
SIMATIC Drive Controller
System Manual, 11/2023, A5E46600094-AD
Glossary
367