Installation guide

V3.8
OnTime Industrial Ethernet
U/R/T200 series Installation Guide
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5 Time synchronization
The T200 can be enabled for time synchronization by ticking the “Enable time sync” box. This
box is only available on the T200 switches (i.e. Westermo OnTime switches with hardware
level time stamping support).
Press the ‘Set’ button and then the ‘Reset’ button to restart the Switch after any changes
performed on the time synchronization parameters.
5.1 SNTP/NTP server or IEEE1588 GrandMaster
The time server protocol is specified by selecting wither the “SNTP/NTP time server” or
“IEEE1588 Grandmaster” tick boxes.
The T200 can be enabled for external time base, i.e. external GPS receiver, if the “Enable
timebase” box is ticked. The internal clock of the switch will be used if the “Enable timebase”
box is not ticked. The user must also specify whether the Acutime GPS receiver is used (the
preferred GPS receiver alternative), or if an off-the-shelf GPS receiver from another GPS
vendor than Trimble is used by enabling or disabling the “Acutime” tick box. An off-the-shelf
GPS receiver must be able to generate NMEA reports on a serial line and an accurate PPS
signal (rise time better than 100 ns), see the Operator Manual for more details.
5.2 IEEE1588 Transparency
A T200 switch should be enabled for IEEE1588 Transparency if this switch is not acting as a
IEEE1588 Grand Master. A IEEE1588 Transparency switch traps IEEE1588 packets that are
sent and received between the IEEE1588 Grand Masters and Slaves. The variable switch
latency of the IEEE1588 SYNC and DEL_REQ through the Transparency switch are
measured and the corresponding FOLLOW_UP and DEL_RESP are adjusted accordingly.
See the Operator Manual for details.
IEEE1588 Transparency is enabled by selecting the IEEE1588 Transparency tick box.
5.3 SNTP time client and serial time server
The switch can also operate as an SNTP/NTP time client. The switch will then perform time
updates versus one or more SNTP/NTP servers in the network in order to update the local
clock of the T200 switch. The SNTP/NTP time servers used for time updates are
automatically detected.
The switch will also act as a time server on the serial interface. Note: the serial interface shall
not be used for interfacing an external GPS when the “SNTP time client” tick box is ticked.
This means that serial enabled devices can be connected to the T200 serial interface and
receive UTC time updates on this interface.
The serial protocol used for serial time synchronization is described in the Operator Manual
and chapter 6.2 describes how to connect serial devices enabled for time client support to the
RS-422 interface of the T200.