Siemens s7-200smart and s7-1200PLC communication technology

This article takes one CPU1215C (6ES7215-1AG40-0AB0) and one S7-200SMART PLC as an example to introduce the S7 communication between them.

Hardware:
S7-1200CPU
S7-200 SMART CPU (firmware V2.0)
PC (with Ethernet card)
TP Ethernet cable

Software:
TIAV16
STEP 7 Micro/WIN SMART V2.1

Completed communication tasks:

The S7-1200 sends 200 bytes in the communication data area DB1 to the VB data area of ​​the S7-200SMART.

S7-1200 reads the VB data area in S7-200SMART and stores it in the data area DB2 of S7-1200.

S7-1200 hardware configuration and network configuration

1 Use TIAV16 software to create a new project, add an S7-1200 station and assign it a network and IP address, as shown in Figure 1-1.

Figure 1-1 Adding S7-1200 station in Botu software

2. Add a new connection for S7-1200CPU in the network view of TIA V16 software, as shown in Figure 1-2:

Figure 1-2 S7-1200 adding a new connection

In the pop-up "Create New Connection" dialog box, select "Unspecified", and then click the "Add" button to add a new connection, as shown in Figure 1-3.

Figure 1-3 Selecting an unspecified connection

You need to specify the IP address and TSAP of the connection partner for the newly created connection. The setting method is shown in Figure 1-4 and Figure 1-5.

Note: TSAP on the S7-200SMART side can only be set to 03.00 or 03.01.

Figure 1-4 Setting the connection partner IP address

Figure 1-5 Setting the TSAP address of the connection partner

TIA software program programming

1. Create a send data block DB1 (similar to the receive area data block DB2). The data block is defined as an array of 200 bytes and the "Optimized block access" option needs to be cancelled in the properties of the data block, as shown in Figure 1-6.

Figure 1-6 Creating a data block and canceling optimized access

2. After the send data block and the receive data block are created, you can call the PUT/GET instruction in OB1 to perform S7 communication, as shown in Figure 1-7.

Figure 1-7 Calling PUT/GET instructions

Table 1. PUT instruction parameter description

Table 2. GET command parameter description

Based on the above steps, the programming of the S7-1200 hardware and software has been completed. Downloading only requires downloading the program to the S7-1200PLC.

Condition Monitoring

1. Connection status monitoring

The successful establishment of the S7 connection is the basis for calling the PUT/GET instruction. Only after the S7 connection is successfully established can the PUT/GET instruction be executed correctly.

In the network view of the TIA software, switch the software to online mode to monitor the S7 connection status, as shown in Figure 1-8.

Figure 1-8 Monitoring S7 connection status

After the S7 connection is successfully established, the S7-1200 triggers the PUT/GET instruction. Through the TIA software monitoring table and the STEP7 Micro/WIN SMART software status table, you can monitor whether the data communication is normal.

Note: The V area in S7-200SMART corresponds to DB1, that is, the communication partner data area ADDR_1=P#DB1.DBX0.0BYTE 200 used in the PUT instruction corresponds to VB0~VB199 in S7-200SMART.

In this document, S7-200SMART acts as the S7 communication server, occupying the server connection resources of the S7-200SMART PLC. The S7-200SMART PLC itself does not need to write a communication program.

Another method for S7-1200 to communicate with S7-200SMART S7 is to use S7-200SMART PLC as the client and S7-1200 as the server. This method requires S7-200SMART to call PUT/GET instructions, and the S7-1200 side does not need to write a communication program.