Communications Capabilities
S5-115F Manual
Safety-related connection of several S5-115F PLCs
Safety-related data exchange is based on the multi-mailbox system. In addition to the two
mailboxes described in Section 7.2.1 for master traffic, there is one mailbox per data path in the
transmitting slave and one per data path in the receiving slave for interslave communication.
The master PLC can be any SIMATIC S5 PLC in which a CP 530 can be used. The master can also
process other, nonsafety-related tasks (e.g. operator-process communication and visualization).
Note
Safety-related data transmission is handled entirely by the operating system. There is
no manipulation of coordination bytes.
You can coordinate data transfer by evaluating reply messages at user level.
SINEC
L1 LAN
Subunit B
S5 - 115F
SIMATIC S5
Subunit A
DI
DQ R - DI
S5 - 115F
Subunit A
DI
DQ R - DI
R - DI DQ DI
Subunit B
R - DI DQ DI
Figure 7-9. Safety-Related Networking of Several S5-115Fs: Single-Channel SINEC L1 LAN
Warning
The sending of a message must not take longer than one SINEC L1 safety time. For this
reason, you must not make any changes to the Send mailbox for this length of time.
Premature alteration of the contents of the mailbox could lead to the undetected loss
of a message. Try to leave as long an interval as possible between two messages.
!
7-14
EWA 4NEB 811 6148-02