Application database (using LLExec)

Objects that can be accessed by an external Master are defined using GF_ProjectVX Code itself. You can begin defining the dictionary of published Modbus objects in the following areas:

• Parameters: where you can insert all of the objects you want to be written just once.
• Status variables: where you can insert all of the objects that can be read/written multiple times.

If you are using a target board that run Axel LLExec runtime the following screen will be displayed when you click the Parameters node: here you can:

• use the Add button to add a new row to the table in order to link one of the published project variables. In the Address column of the table, the Add command will propose the first useful Modbus address, allowing you to change it.
• use the Remove button to remove one or more rows from the grid.
• use the Recalc button to force automatic recalculation of Modbus addresses of the selected rows, starting from address 1. This operation overwrites previous settings.
• use the Assign button to publish, in the Modbus address indicated in the Address column, one of the Automatic variables declared in the PLC project that will become part of the mapped variables (no longer on the Automatic list). If you insert (in the Name column of the table) a variable that is not one of those declared Automatic in the PLC, that variable will be inserted in the appropriate datablock.
• use the UnAssign button to remove an assignment between Modbus address and the variable mapped in the datablock; the variable will appear on the Automatic listof PLC project.

In addition to the Address and Name columns, you can also set the following columns:

• Default value: contains the initial value of the Modbus object.
• Min: contains the minimum value that can be assigned to the Modbus object in ques- tionby the Master by means of a write operation. This limit can be a numerical constant or aparameter (i.e., one of the Modbus objects inserted in the Parameters or Status variables table).
• Max: contains the maximum value that can be assigned to the Modbus object in question by the Master by means of a write operation. This limit can be a numerical constant or a parameter (i.e., one of the Modbus objects inserted in the Parameters or Status variables table).
• Description: contains a brief description of the object.

If you choose the Status variables node, the following screen will be showed in the main area: With regard to the buttons and columns, see the description of the Parameters area.In this case, since the listed objects are RW, you can decide (via the Read only column) whether the object can ONLY be read or read and write by the Master.