ABB Ability 800xA Series User Manual page 107

B Technical Reference
B.6 Redundancy
• 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 (4) if Linking
Device 1 acts as primary device or (5) if Linking Device 2 acts as primary device)
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.
Only one of the listed faults may be present at a time. Another fault cannot be tolerated
until the redundant set has been repaired and a fully operational secondary device
is available.
The following fault conditions cannot be detected and covered:
• a loss of an H1 connection between the primary device and a subset of devices on
an H1 link
• a loss of an H1 connection between the secondary device and the entire H1 link or
a subset of devices on an H1 link.
The conditions for a switch-over from the primary device to the secondary device are
listed below.
Transfer from Primary Device to Secondary Device
The primary device transfers its role to the secondary device
if
or
or
or
1. This requires that at least two 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.
The secondary device accepts the transfer
if
and
and
2PAA114135-610
Host system or configuration tool request to transfer the role.
The primary device detects a failure of its own Ethernet port.
The primary device detects a failure on at least one H1 interface.
The primary device detects a loss of the connection to all devices
1
on an H1 link.
Its H1 interfaces are operational and faultless.
Its Ethernet port is operational.
It has a valid configuration.
107