Siemens ET 200SP Operating Instructions Manual page 65

● TeleControl Basic
The forced image mode
If the send buffer reaches a fill level of 80%, the CP changes to the forced image mode.
New values from data points configured as an event are no longer added to the send
buffer but rather they overwrite older existing values in the image memory.
When the connection to the communications partner returns, the CP changes back to the
send buffer mode if the fill level of the send buffer has fallen below 50%.
● DNP3 / IEC
If a send buffer fill level of 100% is reached, the oldest values are overwritten.
When using the DNP3 protocol, additional conditions for sending the events can be
specified:
– A maximum number of events in the send buffer, configurable for each event class.
– A configurable maximum storage period for events in the send buffer.
Types of transmission
The following types of transmission are possible:
● Transfer after call (class 0)
The current value of the data point is entered in the image memory of the CP. New
values of a data point overwrite the last stored value in the image memory.
After being called by the communications partner, the current value at the time is
transferred.
● Triggered (events)
The values of data points configured as an event are entered in the image memory and
also in the send buffer of the CP.
The values of events are saved in the following situations:
– The configured trigger conditions are fulfilled (data point configuration > "Trigger" tab,
– The value of a status bit of the status of the identifiers of the data point changes see
Event classes with the "Triggered" type of transmission
Depending on the protocol used the following event classes are available:
● TeleControl Basic
– Every value triggered
– Current value triggered
CP 1542SP-1, CP 1542SP-1 IRC, CP 1543SP-1
Operating Instructions, 01/2017, C79000-G8976-C426-03
see below)
also the section Status IDs of the data points (Page 67).
Each value change is entered in the send buffer in chronological order.
Only the last, current value is entered in the send buffer. It overwrites the value stored
there previously.
4.5 Telecontrol communication (CP 1542SP-1 IRC)
Configuration and operation
65