Hello, I try to find informatomation, but not successful. How to know PLC, that visu HMI application is starting. When started VISU then set variable. I don't find information how need do that.
What values need to write to ObjType and FirstObj of function block "Read_var" in order to I will read modbus address 1296
Hello, Somebody have suggest how need read data from slave using modbus RTU. I am using M241 PLC and read_var function. The picture you can see my PLC program. The data of slave is placed 3394 address. Then I try to read, always "READ_VAR" function get "CommError" which number is 254 that means "The detected operation error contains protocol- specific code" and "OpenError" which number is 3 that means I don't know. How need read from slave data, which modbuss adress is 3394 using Read_var functi...