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Entry type: FAQ Entry ID: 16649795, Entry date: 08/15/2003

How do I create a Fetch/Write-connection (S5-compatible communication) to SIMATIC S7 for the SIMATIC NET-OPC Server via Ethernet with the SIMATIC NET CD 07/2001 or higher?

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This example deals with a common network adapter which performs the Fetch/Write-Communication via the OPC Server with a S7-Control at the Ethernet-Network.

The same procedure is also valid for the CP1613.

General Information:

Two configuration-tools are differentiated:

  • NCM PC: 
    NCM PC is furnished with the SIMATIC NET CD and enables to create PC Projects and to open STEP 7-Projects. However, an editing of S7-Blocks in  the STEP 7-Project is impossible with this Software.
  • STEP 7:  
    STEP 7 is installed as full version on your PC. An Installation of NCM PC is not required. The configuration of the PC Station is conducted by the already  installed STEP 7 Package.

Configuration of the PC-Station: 
After the successfully completed Hard- and Software-Installation and the PC-Restart the first step of commissioning wizard appears:

Fig. 1: SIMATIC NET Commisssioning wizard after PC-restart

The steps depend on the number of the recognized components on your PC. The more components are on the PC, the more steps are conducted. By clicking to "Next" you get to the next page.

Fig. 2: SIMATIC NET Commissioning wizard - determination of the operation of the network adapter.

You can set the module to two operation modes:

  • "Use module for productive operation in configured PC station. "
    This option has to be chosen if you want to communicate with the OPC-Server Server via this network adapter.  
  • "Use module for PG operation only"
    This option is chosen if you want to run this network adapter with STEP 7 for Online-Functions or if you want to use it as normal office communication card. That option is not mentioned in this FAQ.

=> Choose here "Use module for productive operation in configured PC station".

Via "Next" you get to the next dialog:


Fig. 3: SIMATIC NET Commissioning wizard - Use OPC-Server

At this stage you can decide via which interface you like to get access.

  • "OPC-Server in configured PC-Station", communication via a OPC-Client.
  • "Configure additional applications", communication with another application, e.g. C-Interface.

=> Choose here "OPC-Server in configured PC-Station".

Click to "Next" to save the configuration.

Fig. 4: SIMATIC NET Commisssioning wizard - Save Configuration

By clicking on "OK" the created configuration is saved. By means of the "Components Configurator" you can verify whether the configuration was accepted. The configurator is also available via the Icon on the desktop.

Fig. 5: Start "Component Configurator"  

In "Component Configurator" the configuration is now visible as it was assigned in the "Commissioning wizard" : 

  • Index 1: OPC-Server
  • Index 3: Network adapter

Fig. 6: Component Configurator

The next step includes the start of the "SIMATIC NET Configuration editor".

Fig. 7: SIMATIC NET Commissioning wizard - Start Configuration editor

Configuration of a ISO-on-TCP-connection (Communication via IP-Addresses) between the SIMATIC NET OPC-Server and the SIMATIC S7

For this communication an ISO-Transport-connection (Communication via MAC-Addresses) can also be used. The configuration works the same way as the ISO-on-TCP-connection. 

Before you can continue working, you have to tranfer the STEP 7 project to the configuration PC.                               

Two main items are at your disposal in the indicated dialog box:

  1. If you want to expand an existing STEP 7 Projekt choose option "Edit saved configuration ". Look for the project which is to be adjusted and activate the option "Insert/synchronize the local PC configuration in the selected project ".
  2. "Create a new project and configuration" - is used if there is no existing configuration. A new project is created. In the next window, a project name is assigned and the option "Copy local station" has to be selected. Using this option the assistant creates a completely configured PC-station in STEP 7 oder NCM PC.

=> As there already is a S7 Control, select option "Edit saved configuration".

Fig. 8: Edit saved configuration

Via the button "Browse" you can select the existing project and you can add the local configuration of the PC-Station. Set a check mark at: "Insert/Synchronize the local PC configuration in the selected project."

Fig. 9: Select saved configuration

In the next window, the ISO-on-TCP-connections between the SIMATIC S7 and the OPC-Server are created.

Select the option "Edit network and connection configuration".

Fig. 10: Create connection

When you click on "Finish",  NETPro opens. You can start configuring the connection.

Fig. 11:  STEP 7 or NCM PC NETPro

Connect the PC-Station to "Ethernet (1)", to which the SIMATIC 300 Station is also linked. Drag the existing network line of the IE-General in direction to "Ethernet (1)" and delete the "Ethernet (2)" by right-clicking and selecting "Delete".

Fig. 12: Linking of the stations with Ethernet(1)

In order to be able to insert a connection, select the OPC-Server. Create a new conection by going to"Insert > New connection". Select the existing S7 CPU as partner and use as connection type" ISO-on-TCP-connection". 

Fig. 13: Insertion of a new connection in NETPro with STEP 7 V5.2

When you acknowledge the settings with "OK" , the properties dialog shows up. In the register "General", enter "ISO-on-TCP Fetch" at Name (ID and set the check mark at "Active connection establishment".

Fig. 14: Enter connection name and active connection establishment

Go to the register "Options" and select "Fetch Active" under "Mode - Local". To establish this operation mode an active connection setup has to be established by the PC. (s. Fig.14).

Fig. 15: Set mode "Fetch Active"

Finish the dialog with OK.

Create an additional connection via "Insert > New connection". Select the existing S7 CPU as partner aus and use "ISO-on-TCP-connection" as connetion type.

After having confirmed the creation of  the connection with "OK" , the properties dialog box comes up. Enter as name (ID) "ISO-on-TCP Write" and set the check mark at "Active connection establishment".

Fig. 16: Enter connection name and active connection establishment

Go to the tab "Options" and select "Write active" for the Local Mode . To establish this operation mode an active connection setup has to be established by the PC. (s. Fig.16).

Fig. 17: setting operation mode "Write Active"

Finish the dialog with "OK".

When you highlight the OPC-Server in the SIMATIC PC Station, the created connections are indicated in the connection table.

Fig. 18: Created connections in NETPRO

After having created the ISO-on-TCP-connections, the connection configuration is completed. Save and compile the project ("Net > Save and compile"). Doing this, the information are updated in the project.

Fig. 19: Save and compile

The error messages are important. In case of warnings, those should only be regarded as information. However, it is impossible to load the configuration if errors ocurre.

After highlighting the symbol "SIMATIC PC-Station", the table with the created connection inside the display will disappear.

Load the configuration locally to your PC in NetPro via "Target module > PLC download to current project > Selected Station"

Fig. 20: Load target module

You are reminded of the fact that existing data on the according components are deleted by the loading procedure and are loaded with the new information.

Fig. 21: Stop target modules

By pushing "OK" the loading procedure is conducted which might lead to the following error message: "The Station manager is not accessable". The entry-ID 12033912 on the Internet includes an explication of potential causes for that behaviour.

After having loaded the PC-Station, you have to load the S7 control the same way you did it with the PC-Station ( Highlight S7 Station > Load target module ).

If the loading procedure does not turn out to be successful, copy the entire project to your PG or your PC. From there, load the configuration via MPI to the S7. 

Finish NETPro and return to the commissioning wizard.

Inside the "SIMATIC NET commissioning assistant" click to "Next".

A symbolics file is not convenient, click to "Next" and "Finish".

Fig. 22: Finish the SIMATIC NET Commissioning Wizard

You can now start the OPC-Scout via "Start > SIMATIC > SIMATIC NET > Industrial Ethernet > Softnet Industrial Ethernet > OPC Scout". 

Connect to the OPC-Server by doubleclicking "OPC.SimaticNet" .Enter a self-created group name inside the dialog box and acknowledge it with "OK".

Fig. 23: Connecting with OPC Server and creation of a group

After having created the group, double-click on it and the "OPC-Navigator" will open. You can now see your protocols in the OPC-Navigator. Doubleclick "SR", your configured group names appear.

Fig. 24: OPC-Navigator

Select the "ISO-on-TCP-Write" connection. Two items appear in the middle window. Move one of the two items with the push button "-->" into the right window. Doubleclick the item in the right window.

Fig. 25: Define items in the OPC-Navigator

In this example, the receiving area of the CPU is located in DB10. The DB10 has to be created with a sufficient length of data inside the control. The Item for the writing process from PC to CPU is configured in DB 10 as of the WORD 0 with 25 words.

Click on "Modify Item".

You can find more information to the Syntax in the manual "Industrial communication with PG PC" in the SIMATIC NET Start menu.

Fig. 26: Modify an Item

Highlight the "ISO-on-TCP Fetch"-connection in the tree structure. Two items appear in the middle window. Move one of the two items with the"-->" push button area to the right window. Doubleclick on the item in the right window.

Fig. 27: Define items in the OPC-Navigator

For this example, the sending area of the CPU is located in DB10. The DB10 has to be created with a sufficient length of data inside the control. The Item for the receipt event of the CPU-Data is declared inside DB 10 as of the word 0 with 25 Words.

Click "Modify Item ".

More information regarding the Syntax can be found in the manual "Industrial Communication with PG PC" in the SIMATIC NET Startmenu.

Fig. 28: Modify item name

Finish the dialog with "OK".

The items are inserted in the OPC-Scout . In case the quality of the first item is good the Fetch-connection to the S7 was established.

Fig. 29: Items in the OPC-Scout

By doubleclicking the column "Value" of the Item "Write" you are enabled to send values to the control.

Fig. 30:  Sending values to the control

If the number of the entered values is not in accordance with the declared area of 25 words the values can not be written in the control.

A successful sending of values to the S7 is indicated in the OPC-Scout via the columns "write result" and "error" The columns "write result" and "error" can be visualized via the menu "view > Options".

Fig. 31: Writing task successful

The quality of the "Write"-Item is always "invalid", as this connection is only a one-sided one. The quality of the connection can not be verified.

Advanced PC Configuration, Fetch/Write connection, loading Netpro loading HW Config , Getting Started, Ethernet connection, OPC Server , Creating connections, loading connections,Simatic Net PC Software, Configuration, Guideline, Guide, Instruction, step by step, OPC Server, Softnet IE, CP1613, Softnet S7, LSAP, Send/Receive, Send/Recv, S7 1613

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