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Device handbook SINEAX DM5000
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Time synchronization via NTP protocol
For the
time synchronization
of devices via Ethernet
NTP
(Network Time Protocol) is the standard.
Corresponding time servers are used in computer networks, but are also available for free via Internet.
Using NTP it's possible to hold all devices on a common time base.
Two different NTP servers may be defined. If the first server is not available the second server is used for
trying to synchronize the time.
If a public NTP server is used, e.g. “pool.ntp.org”, a name resolution is required. This normally happens
via a
DNS server
. So, the IP address of the DNS server must be set in the communication settings of the
Ethernet interface to make a communication with the NTP server, and thus time synchronization, possible.
Your network administrator can provide you the necessary information.
The time synchronization of the Standard interface can be performed via a
TCP ports
The TCP communication is done via so-called ports. The number of the used port allows determining the
type of communication. As a standard Modbus/TCP communication is performed via TCP port 502, NTP
uses port 123. However, the port for the Modbus/TCP telegrams may be modified. You may provide a
unique port to each of the devices, e.g. 503, 504, 505 etc., for an easier analysis of the telegram traffic.
Independent of these setting a communication via port 502 is always supported. The device allows at
least 5 connections to different clients at the same time.
Firewall
Due to security reasons nowadays each network is protected by means of a firewall. When configuring the
firewall you have to decide which communication is desired and which have to be blocked. The TCP port
502 for the Modbus/TCP communication normally is considered to be unsafe and is often disabled. This
may lead to a situation where no communication between networks (e.g. via Internet) is possible.
6.4.2 Connection of the standard interface
The RJ45 connector serves for direct connecting an Ethernet cable.
Interface: RJ45 socket, Ethernet 100BaseTX
Mode:
10/100 MBit/s, full / half duplex, Auto-negotiation
Protocols: http, Modbus/TCP, NTP
Functionality of the LED's
•
LED left: Switched on as soon as a network connection exists (link)
•
LED right: Switched-on during communication with the device (activity)