Point-To-Point Link
S5-95U, Second Serial Interface
Point-to-point link with SINEC L1 protocol and S5-95U as a communication partner
The point-to-point link is a special case of SINEC L1 communication. A SINEC L1 LAN is reduced to
two nodes.
Data, logic control and error detection and correction data can only be exchanged between two
communication partners.
The communication partners are not equal, there is one (point-to-point) master and one (point-to-
point) slave. The slave can only send data after a request from the master.
Figure 2-2 Structure of a Point-To-Point Link with BT 777 Transceiver
Master
BT 777 transceiver
Slave
Restrictions as compared to a SINEC L1 LAN:
•
Communication possible with exactly one slave
•
In the point-to-point link, a programmer cannot be connected additionally.
Special features of the S5-95U in a point-to-point link:
•
The S5-95U is master for the communication partner. Only the SI2 interface has master
capability.
•
The S5-95U can be slave for the communication partner. Both serial interfaces have slave
capability.
For cost saving, one can renounce the BT 777 transceiver if both communication partners are linked
via a special cable (direct cable).
Figure 2-3 Structure of a Point-To-Point Link with Direct Cable
S5-95U
SIMATIC
PLC
Special cable ( Section 2.1)
Data transmission and parameter assignment always correspond to SINEC L1 communication via
the SI1 interface of the S5-95U ( Section 2.2).
2-2
EWA 4NEB 812 6095-02
