The BCNet communication module enables Ethernet communication between PLCs such as S7300 and S7200 and PLCs such as S7-1200, S7-1500 and S7200 Smart through simple command configuration. This example takes S7-1200 and S7-300 as an example, and S7-1500 and SMART 200 follow similar steps.
DB9 serial port of BCNet-S7300Plus connects to the MPI port/DP port of S7-300; S7-1200 comes with an Ethernet port to connect to the Ethernet port of BCNet (multiple PLCs are connected through a switch).
1, Open TIA portal V14, create a new project, configure it, and connect the PLC.
2,Select CPU, right-click PLC, select Properties
3, Configuration Properties
 Select protection.
 Access permission is set to full access permission;
 check the box to allow access from remote partners (PLC, HIM, OPC) using PUT/GET communication.
 click to confirm the download.
Configure BCNet module data exchange commands
1, open BCDevice, search for BCNet-S7300Plus and select [Modify Device Parameters].
2, Create a new client
[ Click on Data Exchange and right-click to create a new client 0.
 The IP address of the remote server is the IP address of the S7-1200, set here to 192.168.1.178; the communication port number of the remote server, default is 102; the connection timeout time is 10S by default.
 Local/Remote TSAP
Local TSAP Remote TSAP
Any 01 00/01
Any 02 00/01
Any 03 00/01
 Click Confirm to create the client.
3,Configure the data exchange command in the client
 Click the New command (transfer the data of 5 words starting from DB1.DBW100 of S7-300 to 5 words starting from DB100.DBW0 of S7-1200)
 Select [Local → Remote] to transfer 5 words; transfer timeout setting layer 2S.
 local site (S7-300) set the station address of the PLC on the bus where BCNet is located, select DB block for the data area, DB number 1, byte offset 100, bit offset ignored.
 No need to set the PLC address of the remote site (S7-1200), select DB block for the data area, DB number is 100, byte offset is 0, and bit offset is ignored.
 Click the “Check” button to check the rules, click the “Confirm” button to generate the command.
4, Client monitoring
Click the client monitoring button, [error message] is no error, and [correct] has data jumping, which means the communication is successful.
Verify the data exchange
1,Open the variable table of SIMATIC Manager and modify the data of DB1.DBW100 to BC12H;
2, open the TIA portal V14 variable monitoring and forcing table and perform data monitoring on DB100.DBW0 with the value BC12H.