How do you configure time synchronization in a SINAUT network?
In the SINAUT ST7 system it is possible to have a uniform time synchronization of all SINAUT nodes. This gives the process data a unique time stamp. In the case of stations that are connected via a dial-up network, you can also use the time synchronization to regularly check the availability of these stations and retrieve the data stored there during synchronization.
Synchronization is implemented as follows:
- MPI/classic WAN:
The time is synchronized via a master TIM with integrated DCF77 radio clock receiver.
A master TIM with DCF77 radio clock receiver is absolutely necessary when implementing a centralized control PC (SINAUT ST7cc or ST7sc) connected to the MPI bus.
- Industrial Ethernet / IP-based network:
The time is synchronized via the centralized control PC (SINAUTST7cc or ST7sc). This means that the centralized control PC is the time master for the master TIMs that are connected to the PC via Industrial Ethernet. The PC is also the time master for the station TIMs if these are connected directly to the centralized control PC via an IP-based network, i.e. not via a master TIM. The centralized control PC must have the exact time in this case. Either the PC itself has a radio clock or it receives the current time from an NTP (Network Time Protocol) server. Look for an NTP server that is compatible with the NTP daemon of the NTP reference project at http://www.ntp.org/.
More details on the topic of time synchronization are available in the SINAUT ST7 System Manual, Volume 2: Software, Edition 05/2007, (see section 2.4 "Configuring stations in hardware configuration", "Time Service" tab), Entry ID: 24619519.
- If there are multiple TIM modules in the centralized control PC on the MPI bus, set the same time synchronization parameters for all the TIMs. The TIMs automatically select a time master on the MPI bus. If it fails, another TIM takes over the function.
- When using TD7onTIM you do not activate time synchronization for the CPU on the station TIM. Although there is no SINAUT program in the CPU, the CPU can be provided with the time as required. The TIM provides its local CPU with the time via its I/O addresses. The CPU's user program reads the time from there. More information is available in the SINAUT ST7 System Manual, Volume 2: Software, Edition 05/2007, (see section: Synchronization of the CPU time with TD7onTIM), Entry ID 24619519.
|1||Ethernet: Double-click on the master TIM. A window with the TIM properties opens.|
|2||In the "Time Service" tab you select the Ethernet interface via which the TIM is connected to the centralized control PC (SINAUT ST7cc or ST7sc) and make the following settings (see Fig. 2). Set a time base of 1 minute. A time base of longer than 1 minute is considered to be an error by ST7cc and ST7sc that is indicated by a corresponding error message. In the "Synchronization field" you select "no", because the master TIM behaves as a slave for time synchronization in this network. (The TIM requests a synchronization for ST7cc/ST7sc in the time base specified.)|
Make the same setting for each other master TIM in the Industrial Ethernet.
|3||SINAUT network: If the stations are connected via a classic WAN, then make the settings as shown in Table 1(Steps 3 to 5). If the stations are connected via an IP-based network, make the following settings:
If the station is connected via a charged IP-based network, e.g. via GPRS, you set a longer time base, e.g. 1 hour.
|4||CPU: If you want the CPU to be time synchronized to a station and you are using the SINAUT program TD7onCPU for the SINAUT communication, then on the station TIM you activate time synchronization on the S7-300 backplane bus or Ethernet (as shown in step 2; recommended time base: 1 minute). In the SINAUT program in the CPU (TD7onCPU), you call the "TimeTask" block from the SINAUT library so that the CPU can receive the current time from the TIM. (More information is available in the "TimeTask" block description.)|