Hi, I downloaded the Modbus RTU library (v11) and I was wondering if there are any examples on how to use the blocks. I am not clear yet on how to input the values for the Inout parameters or what to put in them (I don’t fully understand the description given in the library’s manual). The fields are: udtMBData arrInputData arrOutputData I hope you can help Kind regards, Martin J
There are examples given in Chapter 33 of the manual. I assume you’re implementing a Modbus master, using something like the MB_AXL_F_RSUNI_Master function block? That is, a Modbus device that reads and writes data from a Modbus slave? On the MB_AXL_F_RSUNI_Master function block instance: udtMBData - the same variable needs to be used in all the corresponding Functions (e.g. FC4, to read input registers from a slave). arrInputData - only needs to be connected to the Input Process Data on the corresponding serial I/O module (e.g. via Port connections). arrOutputData - only needs to be connected to the Output Process Data on the corresponding serial I/O module (e.g. via Port connections) You don’t need to read or write any data in these structures/arrays yourself. If the examples are not clear, please let us know.