Broadcast Request ("Transmit To All") - Siemens SIMATIC S5 Manual

Data Transmission Using a Standard Connection
4.6

Broadcast Request ("Transmit to All")

"Broadcasting" means that one active station transmits a message to all active and all passive
stations.
Active
stations
Bus
Passive
stations
Broadcasting
Figure 4-8. Example of a Hardware Configuration for a Broadcast
The sender's prerequisites for broadcast transmission are as follows:
• The parameters for the locations of CBS and SF are set in data block DB1 (see section 4.2).
• Send data and additional information are transferred to the send mailbox.
• The receiver's address "255" (hexadecimal) for a broadcast is entered in byte 2 of the send
mailbox (see section 4.3).
The receiver's prerequisites for broadcast transmission are as follows:
• In an active station: At least CBR and RM are set up.
• In a passive station: Only CBR and RM are set up.
Note
Bits 1, 3, and 4 in the CBS (see section 4.3) are not relevant for broadcast jobs
because the receiver does not acknowledge broadcast transmissions.
4-14
S5-95U
SC
(Sender)
SC
S5-95U
(receiver)
S5-95U, SINEC L2
S5-95U
. . .
(receiver)
. . .
EWA 4NEB 812 6112-02