Setting the clock system

The SIMATIC Drive Controller supports isochronous mode for the following clock systems:

PROFINET IO interface X150

PROFIBUS DP interface X126

Technology I/Os X142

With PROFIdrive Integrated

You can operate the clock systems separately or coupled on an isochronous basis. Exception: Isochronous coupling of the PROFIBUS DP interface is not possible. You can find information on the combinations in which you can couple the clock systems in Overview of isochronous mode.

You make the required settings in the relevant clock systems.

Once you have set and, if necessary, coupled the clock systems, you need to couple the OB servo with the clock system in which you wish to operate the drives / that is the leading clock system.

SINAMICS Integrated clock system

Proceed as follows to set the clock system of the SINAMICS Integrated:

Switch to the network view.

Click on PROFIdrive Integrated in the network view.

Make the settings for the SINAMICS Integrated under "Constant bus cycle time".
The SINAMICS Integrated is always isochronous (option is always selected).


图片: SINAMICS Integrated (PROFIdrive Integrated) clock system

Adjust other settings if required – for example times Ti/To for reading in/outputting data in isochronous mode.

X142 technology I/Os clock system

Proceed as follows to set the clock system of the X142 technology I/Os:

In the device view of STEP 7, select the CPU of the SIMATIC Drive Controller.

Navigate to "Advanced configuration" > "Isochronous mode" in the properties of the CPU.

Select the required settings from the "Source of send clock" drop-down list in the "Isochronous mode for local modules" section.


图片: Technology I/O clock system

PROFINET IO interface X150 clock system

Proceed as follows to set the clock system of PROFINET interface X150:

Select the PROFINET IO system in the network view of STEP 7.

Make the settings for the send clock, etc. under "PROFINET subnet" > "Domain management" > "Sync domains".

In coupled isochronous mode with other clock systems, the clock system of the PROFINET interface is always leading.

You can find additional information on configuring isochronous mode on PROFINET IO in the Isochronous mode function manual.

PROFIBUS interface X126 clock system

You must follow the rules below during configuration if you want to operate the PROFIBUS DP interface in isochronous mode:

Consistency checks ensure that the setting is correct.

Proceed as follows to set the clock system of the PROFIBUS interface:

Select the DP master system in the network view of STEP 7.

Make the settings for the DP cycle under "Constant bus cycle time".

Synchronizing MC Servo with clock system

Proceed as follows to synchronize the MC Servo with a clock system:

Open the "Program blocks" folder in the project tree.

Select the "MC Servo" organization block.

Select the "Properties" command in the shortcut menu.

Select the "Cycle time" entry in the area navigation.

The option "Synchronous to the bus" must be selected in the dialog box.

In the "Source of send clock" drop-down list, select the clock system to be synchronized with the OB MC‑Servo.


图片: Synchronizing MC Servo with clock system

For coupled isochronous mode, you must always select the leading clock system.

Setting the application cycle

The application cycle of MC Servo is derived from the send clock and a configurable factor. The adjustable factors depend on the coupled clock system.