About using UBIQUITY in combination with Simatic Step 7

Why do the UBIQUITY interfaces in the PC/PG interfaces list appear in the Simatic Step 7 software with a warning symbol (yellow triangle)?

The problem can be very likely due to an incorrect update of the interface list after upgrading of the UBIQUITY VPN virtual interface driver.

To solve the problem simply delete the driver database created by the Step 7 software for each communication interface.

Firstly, close the Step 7 software if it is running.

The database is located in different positions according to the operating system of the computer where Step 7 is installed.

For Windows XP, the database is in the Windows registry. You need then to use the registry editor to locate the following path:


and then delete all the registry keys related to the UBIQUITY interfaces in it.


It is strongly advised to back-up the registry before starting.

For Windows 7 or Windows 8, the driver database consists of a set of XML files stored in the following path:

C:\ProgramData\Siemens\Automation\Simatic OAM\data\LogDevices

From that folder you need to remove all the XML files related to the UBIQUITY interfaces.

Now restart the Step 7 software to automatically recreate the database entries.

Setting the PG/PC interface in Siemens Step 7

This note refers to the use of Siemens Step 7 software in the case the PG/PC interface is set to use the “Auto” mode as shown in the following figure.


With this mode the Step 7 software can dynamically assign the IP to the communication interface of the PC to communicate with the PLC nodes.

For the use with UBIQUITY, it is suggested to disable this mechanism by selecting the option “Do not assign IP addresses automatically”, as shown in the following figure.


This automatic mechanism is in fact not needed as UBIQUITY already assigns to the UBIQUITY VPN adapter a real IP which is compatible with the remote sub network.

Network configuration in Simatic Step 7 NetPro

The use of the MPI gateway service requires a specific network configuration of the Simatic Step 7 project.

The configuration is executed using the Simatic Step 7 “NetPro” utility.

The network topology is shown in the following figure.


The settings, required by the PG/PC object, are defined by an IP address assigned to the PC where the Step 7 software is running. To view the settings, refer to the “Parameters” tab of the “Properties - Ethernet Interface” section.

The object named “UBIQUITY Router” is a component of “Simatic PC Station” type available in the object folder as shown in the following figure.


NetPro supports default configuration block imports. To assist network setup by users, a configuration block which can be directly imported in the NetPro software has been prepared. The block is called “ASEM UBIQUITY MPI.cfg” and can be downloaded in the “Support” section of the UBIQUITY area on the ASEM web site.

In NetPro, select “Import” in the “Edit” menu and select the “ASEM UBIQUITY MPI.cfg” file.

The gateway will be imported in the network configuration and will appear as shown in the following figure.


Double-click on the green “IE General” box as shown in the figure above to open the Gateway Ethernet interface configuration screen.

Once you have opened the screen on the “Parameters” tab, please note that you must NOT select the “Set MAC address/ Use ISO protocol” option.

Enter the IP address of the UBIQUITY Router LAN port in the IP address field (in this example: Enter the mask corresponding to the sub network you are configuring in the mask field.

Select “Without Router” in the “Gateway” area.

Now add a PG/PC station to the network layout using the “AddNetwork elements” path.

Double-click on the PG/PC station to add an unconnected PG/PC station.


Right click on PG/PC and click on “Object properties…”, select the “Interface” form and press “New type…”.

Select “Industrial Ethernet” and press OK.


Make sure that “Set MAC address/Use ISO protocol” is not selected on the “Parameters” form (item 2).

Set the IP address and the subnet mask assigned to the “UBIQUITY VPN” virtual network interface when the VPN connection is established.

Check the “Without router” box.

In the “Subnet” area (located in the bottom of the window), select the network to which the “ASEM UBIQUITY MPI” device is connected. Double-click on OK to close the two Property windows.

At this point, the network layout will appear as shown in the following figure.


The PG/PC programming interface can now be assigned.

To do this, right-click on PG/PC and click on “Assign PG/PC”.


On the “Assign” form of “Unassigned PG/PC interface parameterizations” properties, select the TCP/IP interface which is used to connect to the Ethernet.

The “TCP/IP (Auto) -> UBIQUITY Ethernet Adapter” interface must be set to use the UBIQUITY service.

Then press the “Assign” button and press OK to confirm.

The network layout will appear as shown in the following figure.


The connection shown in yellow in the PG/PC figure above indicates that this object will be used to access the network.

The orange background behind the other objects informs the user that the last changes have not be saved and compiled.

The last step is to compile and save the network layout of the project.

Select “NetworkSave and compile…” to do this.