1/29/2011 4:32 PM | |
Joined: 9/27/2006 Last visit: 9/19/2024 Posts: 12282 Rating: (2684) |
Hello R&H CO; Q1)The PLC is a Slave device? The S7-200 can be setup as either a master or a slave over serialModbus (RTU), if you have purchased the Modbus libraries from Siemens,6ES7 830--2BC00--0YX0. Remember that there must be one master per Modbus network, and only one. Q2)Dose the library of the MODBUS have only this 2 Instruction? I suggest you look at the chapter on Modbus in the S7-200 System manual to look at the different Modbus functions used for the master and slave programs: S7-200 System Manual Q3)is There any file help me to understand the MODBUS Network ? The S7-200 System manual chapter on Modbus has a very good resumé on the basis of Modbus. Look also ot the attached document form Modicon, explaining the use of Modbus with their PLCs. Examine especially the relationship between Modbus addressing and Modbus functions: for example, calling Modbus function 04 implies you will be reading registers at address 30000 and higher, using Modbus funcruion 16 means you intend to write to addresses 40000 (more than one at a time). Hope this helps, Daniel Chartier AttachmentPI_MBUS_300.pdf (87 Downloads) |
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