Mb_Client Example 2: Multiple Requests With Different Tcp Connections - Siemens SIMATIC S7 System Manual

Hide thumbs Also See for SIMATIC S7:

Table of Contents

MB_CLIENT example 2: Multiple requests with different TCP connections

Modbus client requests can be sent over different connections. To accomplish this, different

instance DBs, IP addresses, and connection IDs must be used.

The port number must be different if the connections are established to the same Modbus

server. If the connections are on different servers, there is no port number restriction.

The example shows both clients writing to the same memory area. Also, a returned error is

captured which is optional.

Modbus function 4 - Read input words (in S7-1200 memory)

Modbus function 3 - Read holding register words (in S7-1200 memory)

S7-1200 Programmable controller

System Manual, 11/2011, A5E02486680-05

105BCommunication processor

12.5 Modbus communication

Show Quick Links

Table of Contents

Simatic s7-1200