5.7 Configuring the CPU for communication
All IP addresses are configured when you download the project.
Table 5- 10
synchronization using Network
Time Protocol (NTP) servers
Time synchronization interval
PROFINET device start-up time, naming, and address assignment
PROFINET IO can extend the start-up time for your system (configurable time-out). More
devices and slow devices impact the amount of time it takes to switch to RUN.
In V4.0, you can have a maximum of 16 PROFINET IO devices on your S7-1200 PROFINET
Each station (or IO device) starts up independently on start-up, and this affects the overall
CPU start-up time. If you set the configurable time-out too low, there may not be a sufficient
overall CPU start-up time for all stations to complete start-up. If this situation occurs, false
station errors will result.
In the CPU Properties under "Startup", you can find the "Parameter assignment time for
distributed I/O" (time-out). The default configurable time-out is 60,000 ms (1 minute); the
user can configure this time.
PROFINET device naming and addressing in STEP 7
All PROFINET devices must have a Device Name and an IP Address. Use STEP 7 to define
the Device Names and to configure the IP addresses. Device names are downloaded to the
IO devices using PROFINET DCP (Discovery and Configuration Protocol).
Parameters for time synchronization
Click the checkbox to enable time-of-day synchronization using
Assigned IP Address for network time server 1
Assigned IP Address for network time server 2
Assigned IP Address for network time server 3
Assigned IP Address for network time server 4
Interval value (sec)
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG