LM small programmable controller software (based on CoDeSys) note XXI: error 3703

  When writing a program , Inadvertently entered two new variables in the global variable , And they didn't change the default name , Their names are name, So this error will be reported .

This paragraph in English is ：several declarations with the same identifier "name"

Several declarations have the same identifier “name”

It means that the names of two variables are the same .

It's easy to change , Just delete one of the variables .

What is a global variable

It is well known throughout the whole project “ The standard ” Variable , Constants or remaining variables can be declared as global variables , It can also be used by other network users to exchange data Network variables .

Be careful ： In a project, you can define a local variable with the same name as the global variable . under these circumstances , stay POU Use local variables in the scope of .

Two global variables with the same name are not allowed . for example , If you are in the PLC A variable is defined in the configuration “var1”, At the same time, this variable also exists in the global variable list , Then you will get compilation errors .

Create a list of global variables

To create a list of global variables , Open ' resources '  , Select the entry ' Global variables ', Or choose an existing list . next , Select the command ' engineering ' ' object ' ' add to ' To open the global variable list dialog .

If an existing global variable list is marked in the object manager , Then you can also use instructions ' engineering ' ' object ' ' To configure ' Open its dialog .

Link to the file ：

file name ： If there is an output file (*.exp) Or a DCF file , These files contain the desired variables , Then you can establish a link to this file . In order to do this , To insert the path of the file in the file name field . Click the Browse button to get the standard dialog box ' Text file selection '. When reading them ,DCF File is converted to ICE Format .

If you want to read the variable list from an external file before each project is compiled , Then activate the pre compile input option . If you want to write the variable list to an external file before each project is compiled , Then activate the pre compile output option .

If you click OK To close ' Global variable list ' Dialog box , Then you create this new object . The list of global variables is marked in the object manager   To mark . You can use it. ' engineering ' ' object ' ' The props ' Command to reopen ' Global variable list ' Configuration dialog .