Instructions:
When addressing the data area of a SIMATIC S7-200 CPU via the OPC Scout, note that you must take into account the OPC server object model when creating a variables link. Access to the variables area is always via the DB1 of the S7-200 CPU. The example below of a variables area in DB1 of the S7-200 CPU explains how to proceed with SIMATIC NET OPC Scout.

The requirement is an existing connection from the OPC server to an S7-200 CPU.

1. Start the OPC Scout and double-click on the object "OPC.SimaticNET". 
2. Add a new group and assign a new group name of your choice.
3. Acknowledge the dialog with "OK".

Fig. 01  
 

4. Right-click the group you have added and select the function "Add Item". 
5. Select "Connections > S7 > connection name xy".
   ("connection name xy"  represents the name of the connection that you have configured in NetPro. This is a language-specific default name (e.g. "S7-Verbindung_x" [German] or "S7-connection_x" [English]) if you have not changed it in NetPro).
6. Using the "-->" button insert an item into the column "The listed Item(s) will be added to Group:...".
7. Select the newly inserted item and then right-click on it. Select "Modify Item"  from the pop-up menu.

Fig. 02  
 

8. Now you can edit the item. Delete the right section of the string up to the closed square brackets and replace it with a variables area from DB1 according to the following syntax:
   <Data block number = DB1>, <Data type><Byte address in the V memory>, <Number of values of the data type specified>.
   Example: DB1, B2, 3 = in this case access to the V memory starts from the second byte as array with 3 bytes.

Fig. 03  
 

9. Acknowledge the definition of your variables with "Modify Item".
   
   Note:
   If you do not use the "-->" button to copy the connection name into the right-hand table column, but enter it manually, then make sure that it matches the connection name in the left column and thus the NetPro configuration.

Fig. 04  
 

10. Click the "OK" button to transfer the link to the data area of the SIMATIC S7-200 CPU into the item list and the item information is displayed.

Fig. 05  
 

Note:
You can write values to the SIMATIC S7-200 CPU by double-clicking the "Value" field of the item concerned and entering a value.
If you cannot open the S7 window under "Connections", then an S7 connection has not be configured.

Keywords:
OPC client