User Manual Managed Switches
201
Failure Action
Setting
Description
Factory
Default
Nothing
No action when the connected device fails to respond
the alive-checking packets.
Nothing
Restart Forever
Cut power and supply power continuously to the
connected device until it successfully responds the
alive-checking packets.
Restart Once
Cut power and supply power once to the connected
device.
Power On
Supply power to the connected device.
Power Down
Stop supplying power to the connected device.
Reboot Time
Setting
Description
Factory
Default
Number between
3 and 120 (sec)
If the field Failure Action is programmed as “Restart
Forever” or “Restart Once”, this field indicates the
periodicity of the switch to send alive-checking
packets to the connected devices.
3
3.16 PTP Synchronization
NOTE:
Protocol 1588 PTPv2 is only implemented in the models
IE-SW-AL14M-12GT-2GESFP and IE-SW-AL24M-16GT-8GESFP.
IEEE Std 1588-2008 specifies the second generation of the Precision Time Protocol (PTP), which is
also known as “PTPv2” or “1588v2”. This is capable of very accurate time synchronization by using
special Ethernet hardware that records the exact time a PTP synchronization message is received at
the Ethernet card. It achieves clock accuracy in the sub-microsecond range, in contrast with
NTP/SNTP protocol that achieves an accuracy around 1ms.
IEEE Std 1588-2008 defines a number of terms for PTP time synchronization systems:
•
Grandmaster clock
: The clock that is the ultimate source of time for synchronization using
PTP and usually has a GPS receiver built-in
•
Master clock
: A clock that is the source of time that other clocks on the network synchronize
to
•
Slave clock
: The end user of PTP (ex: PLC)
•
Transparent clock
: An Ethernet switch that measures the time taken for a PTP
synchronization message to transit the device and provides this information to clocks
receiving the PTP event message
•
Boundary clock
: A clock that has multiple PTP ports and may serve as a source of time, i.e.
be a slave clock to an upstream source and a master clock to downstream devices
Ethernet switches in a PTP network will generally be transparent clocks but it may also be possible
for them to act as boundary clocks. Weidmüller switches can be programmed for both operation