Chapter 3 PLC System Configuration & Settings Description The parameter names or descriptions are shown in this column. Address Users can set data registers in this column. The parameters in the module which do not need to be updated constantly are stored in the data registers. If users specify data registers for the parameters in the module, and the parameters in HWCONFIG are downloaded to the CPU module correctly, the data registers in the CPU module are synchronized to the parameters in the module when the system operates. As a result, the users can access the module through the data registers.
Accessing a module through the data registers is more efficient than accessing the module through the instruction FROM/TO. Besides, the number of data registers that a module has is limited. When users set data registers, they have to refer to the instructions for the module. As the example below shows, D3000 corresponds to the parameter CH0 Average Time in the Parameter Setting window for AH04AD-5A. After the parameters in HWCONFIG are downloaded to the CPU module, users can change the value of the parameter CH0 Average Time by changing the value in D3000 in the CPU module.
But if users write a value which is not allowed by a parameter into a data register during the operation of the system, the system will restore the value in the data register and the value of the parameter to the original values. *. Please refer to programming manuals for more information about the instruction FROM/TO. 3-233