Interaction Of Ptp And Sntp - Hirschmann RS20 User Manual

Synchronizing the system time in the

8.4 Interaction of PTP and SNTP

According to PTP and SNTP, both protocols can exist in parallel in the same
network. However, since both protocols effect the system time of the device,
situations may occur in which the two protocols compete with each other.
Note: Configure the devices so that each device only receives the time from
one source. If the device gets the time via PTP, you enter the "External server
address" 0.0.0.0 in the SNTP client configuration and do not accept SNTP
broadcasts. If the device gets the time via SNTP, make sure that the "best"
clock is connected to the SNTP server. Then both protocols will get the time
from the same server. The example
GPS
NTP-
Server
SNTP
149.218.112.0
Figure 51: Example of the coexistence of PTP and SNTP
Application example:
The requirements with regard to the accuracy of the time in the network
are quite high, but the terminal devices only support SNTP
156
PLC
SNTP
PTP
SNTP Client SNTP Server
SNTP Server
PTP
149.218.112.1 149.218.112.2
8.4 Interaction of PTP and SNTP
(see fig. 51) shows such an application.
SNTP-Client
PTP
SNTP Server
PTP PTP
149.218.112.3
SNTP
SNTP-Client
(see fig. 51).
Basic Configuration L2P
Release 4.2 07/08