ABB LD 800HSE, Manual

Page: 114 / 136

Fault Domain Appendix C Technical Reference
114 3BDD011677-600 A
Fault Domain
The shaded area in Figure 39 shows the fault domain. Faults within the fault
domain can be detected and covered by the redundancy features. Those are:
• permanent faults within the linking device - (1)
• transient faults within a linking device that lead to loss of functions - (1)
• a loss of the serial connection between the two linking devices - (2)
• a failure in the Ethernet communication between the two linking devices - (3)
• a loss of an H1 connection between the Primary Device and the entire H1 link;
this may be caused by disconnecting an H1 cable from the Primary Device -
(4a) if LD1 acts as Primary Device; (4b) if LD2 acts as Primary Device).
Figure 39. Fault Domain
Detecting a loss of an H1 connection between the Primary Device and the entire
H1 link requires that at least two H1 devices have been connected to that H1
channel of the linking device and have appeared in the H1 Live List before the
loss of the connection occurs.