Pilz PSSnet SHL 8T MRP - Manual (Page 26)

Ring/Network coupling
26
3.1 Variants of the ring/network cou-
pling
PSSnet SHL - Redundancy Configuration
Pilz GmbH & Co. KG, Felix- Wankel Str. 2, 73760 Ostfildern
3.1 Variants of the ring/network
coupling
The redundant coupling is effected by the one-Switch coupling of two ports
of one device in the first ring/network to one port each of two devices in a
second ring/network segment
(see fig. 8) .
Immediately after the main line fails, the device opens the redundant line.
When the main line is OK again, the main line is opened again and the
redundant line is blocked again.
An error is detected and eliminated within 500
ms (typically 150 ms).
The redundant coupling is effected by the two-Switch coupling of one port
each on two devices in the first ring/network to one port each of two devices
in the second ring/network segment
(see fig. 14) .
The device in the redundant line and the device in the main line use control
packets to inform each other about their operating states, via the Ethernet or
the control line.
Immediately after the main line fails, the redundant device opens the redun-
dant line. As soon as the main line is OK again, the device in the main line
informs the redundant device. The main line is opened again, and the redun-
dant line is blocked again.
An error is detected and eliminated within 500
ms (typically 150 ms).
The type of coupling primarily depends on the topological conditions and the
desired level of safety
(see table 4) .