Communication With The Cpu - Siemens SIMATIC TeleControl DNP3 Configuration Manual

Configuration

3.12 Communication with the CPU

3.12 Communication with the CPU
Communication with the CPU
Using the first three parameters you specify the CPU access by the TIM in the CPU scan
cycle. You will find the structure of the CPU scan cycle in the section Read cycle (Page 115).
The fourth parameter "Frame memory size" decides the size of the send buffer of the TIM for
frames of data points that are configured as an event.
● Cycle idle time
Wait time between two scan cycles of the CPU memory area
● Max. number of write jobs
Maximum number of write jobs to the CPU memory area within a CPU scan cycle
● Max. number of read jobs
Maximum number of low-priority read jobs from the CPU memory area within a CPU scan
cycle.
● Frame memory size
Here, you set the size of the frame memory for events (send buffer).
The size of the frame memory is divided equally among all configured communications
partners. For information on the size of the frame memory, see "Performance data and
configuration limits".
You will find details of how the send buffer works (storing and sending events) as well as
the options for transferring data in the section Process image, type of transmission, event
classes (Page 113).
Watchdog bit
● TIM monitoring / CP monitoring
Via the watchdog bit, the CPU can be informed of the status of the telecontrol
communication of the communications module.
CP time
● CP time to CPU
Using this function, the CP can make its time of day available to the CPU.
You will find details in the STEP 7 information system.
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Configuration Manual, 11/2018, C79000-G8976-C508-01
Configuration - DNP3