Time Synchronization - Siemens SIRIUS PROFINET Manual

Certificates:
Certificates are mutually exchanged in order for the web browser to access the web server
via an https connection. On each change of the 3RW44 PN IP address, a unique certificate
with a validity of five years is created for this purpose.
You can also install a CA certificate with a validity up to 2037 via the integrated web server
as follows:
1. Click the "Download certificate" link in the header of the "Intro" start page.
2. Open or install the CA certificate.
Note
Installation of the 3RW44 CA certificate
You only have to install the 3RW44 CA certificate once for the web client in question and it
then applies to all 3RW44 PN devices.
If you do not install the CA certificate, the web browser signals a certificate error when the
connection is established to 3RW44 PN.
Note
The connection between the web server and web client is monitored. If an interruption lasts
at least 10 s, the soft starter signals "Connection abort".
7.4

Time synchronization

Time-of-day synchronization by the NTP procedure
3RW44 PN has a non-battery-backed real-time clock that can be synchronized using NTP.
Network Time Protocol (NTP) is the implementation of a TCP/IP protocol for time
synchronization in networks. The NTP procedure uses hierarchical time synchronization, that
is, an external clock (e.g. SICLOCK TM or a PC in the network) is used for synchronization.
The device transmits time-of-day queries to the configured NTP server at configured time
intervals. Based on the responses of the server, the time of day of the non-battery-backed
clock in the 3RW44 is synchronized. This ensures that a synchronized time of day is
available shortly before the supply voltage is switched on.
In the default setting, the time synchronization is not active.
PROFINET Communication Module for SIRIUS Soft Starter 3RW44
Manual, 12/2013, A5E31996495002A/RS-AA/001
Functions
7.4 Time synchronization
57