Siemens SIMATIC ET 200SP System Manual

Commissioning
11.10 Time synchronization
Distributed I/O system
220 System Manual, 09/2019, A5E03576849-AJ
11.10 Time synchronization
Introduction
All CPUs are equipped with an internal clock. The clock shows:
● The time of day with a resolution of 1 millisecond
● The date and the day of the week
The CPU takes into account the time change caused by daylight saving time.
You can synchronize the time of the CPUs with an NTP server in NTP mode (NTP: Network
Time Protocol).
Operating principle
In NTP mode, the device sends time queries at regular intervals (in client mode) to the NTP
server in the subnet (LAN). Based on the replies of the servers, the most reliable and most
accurate time is calculated and the time of day of the CPU is synchronized. The advantage
of this mode is that it allows the time to be synchronized across subnets. You can
synchronize the time of day of up to a maximum of four NTP servers. You address a
communications processor or an HMI device, for example, as sources for time
synchronization via the IP addresses.
The update interval defines the interval between the time queries (in seconds). The value
range of the interval is between 10 seconds and one day. In NTP mode, it is generally UTC
(Universal Time Coordinated) that is transferred. UTC corresponds to GMT (Greenwich
Mean Time).
NTP server for the ET 200SP CPU
You can assign an ET 200SP CPU to up to 4 NTP servers.
In STEP 7 you enable the time synchronization in NTP mode. You can configure up to four
NTP servers for the ET 200SP CPU in STEP 7.
If you have enabled time synchronization via NTP for the CPU, then you can enter the IP
addresses of up to four NTP servers in the user program. For this, use the "T_CONFIG"
instruction.
Enabling time synchronization via NTP server
To enable the time synchronization for the ET 200SP CPU via NTP servers, follow these
steps:
1. In the Inspector window, navigate in the properties of the CPU to "General" > "PROFINET
interface" > Time synchronization".
2. Enable the option "Enable time synchronization via NTP server".

Siemens SIMATIC ET 200SP Specifications

General

System Type	Distributed I/O System
Mounting	DIN Rail
Communication Protocol	PROFINET, PROFIBUS
IP Rating	IP20
Category	I/O Systems
Supply Voltage	24 V DC
Modularity	Yes
Hot Swapping	Yes
Storage Temperature	-40°C to +70°C
Digital Inputs	Yes
Digital Outputs	Yes
Analog Inputs	Yes
Analog Outputs	Yes
Communication Interface	PROFINET, PROFIBUS
Number of Modules	Up to 64
Relative Humidity	5 to 95% (non-condensing)
Operating Temperature	-25°C to +60°C