Coordinating Data Exchange In The Control Program - Siemens SIMATIC S5-100U System Manual

S5-100U
5. Transfer the changed DB1 to the programmable controller. The default DB1 is overwritten.
If you now go from STOP to RUN or from Power OFF to Power ON (with a battery inserted), the
programmable controller accepts the changed parameters and stores them in the system data area.
13.3

Coordinating Data Exchange in the Control Program

After you set the parameters, the control program for data exchange has to be created. The control
program relies on the coordination information that the operating system makes available in the
coordination bytes (see Figure 13-3).
Sender (source)
RAM
KBS
KBE
Control program
for data exchange
Send Mailbox
Receive Mailbox
L1 bus
Figure 13-3.
In the following paragraphs, you will learn how to control the sending and receiving of data after you
have set the parameters in DB1.
There is an example in section 13.3.3 of how you must program the data exchange in a function
block.
EWA 4NEB 812 6120-02b
Data
area or
flag area
Data Exchange between Sender and Receiver (Principle)
Connecting the S5-100U to SINEC L1
Receive (destination)
RAM
KBS
KBE
Control program
for data exchange
Send Mailbox
Receive Mailbox
Data
area or
flag area
13-7