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Entry type: FAQ, Entry ID: 23972743, Entry date: 10/04/2006

How do you synchronize the date and time between an S7-300/400 and OP3 (C7-621) with ProTool?

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There are two options for synchronizing the date/time between an S7-300/400 and OP3.

  • Transfer date and time from the CPU to the OP3.
  • Transfer date and time from OP3 to the CPU.

The two types of synchronizing date/time between OP3 and S7-CPU are implemented in a STEP 7 project available for downloading at the end of this entry.

Communication between S7-CPU and OP3 is realized through the interface area that has to be inserted under area pointer in the ProTool project.

Fig. 01: Structure of the interface area

The Control and response bits, Date and Time areas are significant for time synchronization.

Transfer date and time from the S7-CPU to the OP3 (FC1 in the STEP 7 project)

In the Control and response bit area, Bit 2 of Byte n+0 signalizes the date/time request of OP3.

Fig. 02: Control/return information bits

Synchronization of the OP3 with the SIMATIC S7 is done in four steps:

  1. Every 15 minutes the OP3 sets Bit 2 in data byte n+0 of the interface area.
  2. When Bit 2 is set, the S7-CPU time must be read out of the CPU with the "READ_CLK" function and copied to the date/time folder of the interface area.
  3. As soon as the S7 program resets Bit 2 the OP3 recognizes that the S7 program has deposed current values for date and time in the interface area.
  4. The OP3 reads the current data from the data bytes n+15 to n+17 and n+21 to n+24 of the interface area and then sets the system time.

Fig. 03: Date and time folder

Transfer date and time from the OP3 to the S7-CPU (FC2 in the STEP 7 project)
If Bit 6 of Bytes n+0 of the Control and response bits is set, a new time has been set on the OP3. If Bit 5 of Byte n+0 of the Control and response bits is set, then the date has been changed on the OP3. The new values for date and time are stored in the date/time folder in the interface area. In the CPU the values must be copied into the corresponding tag area and then the CPU time must be set with the "SET_CLK" function. Bits 5 and 6 are reset after the CPU clock has been set.

More information is available in the OP3 device manual in Entry ID: 1142799.

Copy the "Clk_OP3.zip" file into a separate directory and then unpack the file. You can use the SIMATIC Manager to open and process the STEP 7 project. In order to process the OP3 project you must start ProTool with the option "STEP 7 integrated". The project was created with STEP 7 V5.2 SP1 and ProTool V6.0 SP2.

The download contains the function blocks described above and a sample call from organization block OB1.

Clk_OP3.zip ( 287 KB )

Runnability and test environment:
The following table lists the components that have been used to create this entry and verify the functions described.

Components Product and version designation
PC operating system Microsoft Windows XP SP2
Standard tools -
Engineering Tool STEP 7 V5.2 SP1
HMI software ProTool V6.0 SP2
HMI system -

ProTool Lite, RMOS device


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