Delay Mechanism; Grandmaster Priority; Ptp Messages; Ptp - Configuration Summary - GE Reason RT430 Technical Manual

RT430/434

Delay mechanism

Grandmaster Priority

PTP Messages

PTP - Configuration Summary

58
The RT430/434 is capable of measuring the delay between master and slave clocks
using End-to-end and Peer-to-peer, according to IEEE1588 standard. The field Delay
mechanism allows configuring the type of measurement of the delay, as follow:

End-to-end: measurement of delay across the network between master clock
and slave clock;

Peer-to-peer: measurement of delay only between master and slave clocks as
neighbors.
When configured as master, BMC algorithm tie breaking criteria priorities must be
attributed. The fields Grandmaster priority #1 and #2 allow configuring the priorities
of both Ethernet ports, in which #1 is the first and #2 is the last tie breaking criterion.
Between the first and the last tie breaking criterion, other clock characteristics are
analyzed. The priority values can vary from 0 to 255. The lower the attributed value is,
the higher its priority is.
In PTP protocol, messages containing Sync information and timestamps are sent
across the network in multicast mode.
Announce messages are used to inform devices connected to the network about the
existence of a master clock available to send Sync packets. The clock connected to
the network operating as a master should send Sync messages. In case it is a two-
step clock, Follow Up messages containing the timestamp will be send after the Sync
messages.
In RT430/434, it is possible to choose the frequency to send messages and the
waiting time of Announce message receipt, through the fields below:

Delay request interval allows choosing the frequency to send messages with
delay measurement. It is possible to configure the unit to send 16 messages per
second until one message every-32-seconds.

Announce interval allows choosing the frequency to send messages that apply
the device to become a network master candidate. It is possible to configure
the unit to send 16 messages per second until one message every-32-seconds.

Sync interval allows choosing the frequency to send Sync messages. It is
possible to configure the unit to send 16 messages per second until one
message every-32-seconds.

Announce receipt timeout allows choosing the waiting time of Announce
message receipt when RT430/434 is being used as slave. In case an Announce
message is not received within this time interval, the unit assumes that the
current master clock is unavailable and executes the BMC to select another
master clock. It is possible to configure values between 2 and 255 seconds.
The table below presents all configurable PTP parameters and its possible values and
variables.
Chapter 6 – Configuration
RT430/434