Procedure for communicating with controllers

DataToPLC and DataFromPLC data tables contain the application-specific data fields that are read from and written to the PLC, respectively. When using the EtherNet/IP protocol, the first 32 bytes of each data table (assembly) are reserved for predefined Quick Comm data fields, meaning the first valid address for EtherNet/IP fields starts at 32. When using PROFINET these tables are in separate modules and addresses start at 0. For more information on specific address mapping, refer to the data tables sub-sections found in the sections for either PROFINET or EtherNet/IP.

The following steps describe how to add or edit data fields in the DataToPLC and DataFromPLC data tables, from the Platform Configuration dialog.

1. Open the Platform Configuration dialog, navigate to the DataToPLC or DataFromPLC page, and enter the data table's base address in the PLC's data map.

2. Click on the Add or Delete button to change the number of data fields. The address of data fields are automatically set to the base address plus an offset based on data type, but can also be set manually to another address. Click the Up or Down arrows to change the order of the fields.

3. Assign a name to each field according to its use. For example, using the same name as the tag in the PLC.

4. For each field, select the data type. The data type establishes the size of the field and will offset the address of the next data field by a fixed number of bytes. String type data has a default maximum string size of 10 bytes, but can be changed. The following table shows the different data types of each protocol and their sizes.

   Date type
   EtherNet/IP	PROFINET	Size
   BOOL	Bit	1-bit
   USINT	Byte	8-bit (unsigned)
   INT	Int	16-bit
   UINT	Word	16-bit (unsigned)
   DINT	Dint	32-bit
   REAL	Float	32-bit
   UDINT	DWord	32-bit (unsigned)
   LREAL	Lreal	64-bit
   SHORT_STRING	--	1 + Max string size
   NULL_TERMINATED_STRING	--	1 + Max string size
   --	String	2 + Max string size
   STRING	--	4 + Max string size
   STRING2	--	2 + (2 * Max string size)

5. Change the default address of the data field if it does not match the address in your PLC's data map. This allows you to create a manual offset for the data fields if they are not contiguous in the PLC's memory.

If you need to specify a field linked to a value that will automatically update at inspection end, instead of performing the previous steps, go to the Quick Watch flyout panel of the required result element in a step's display, right-click on the result that you need to add, and choose Auto DataToPLC. This adds a new data field whose name is based on the result name and whose value is a link to the result that you clicked on. The Open DataToPLC button gives access to the corresponding page in the Platform Configuration dialog, where you can modify the name, address in the PLC's data mapping, and data type.

To send application-specific data to the PLC, you write values to the DataToPLC data tables using the ProfinetWriter step or EthernetIPWriter step, or by using the Auto DataToPLC option. Data fields found in the DataToPLC data tables can also be used for validation, for more information on validation see the Project Change Validator overview section in Chapter 62: Project Change Validator.

When the PLC writes a value to a data field associated with an event, the event will cause an associated action (for example, trigger, or reset) or subflowchart to execute when outside the active inspection zone, it is queued otherwise. For more information, see the Configuring actions and events section later in this chapter. You can also use actions to automatically send data, through the DataToPLC data tables, to the PLC. To do so:

1. In the DataToPLCDataToPLC page, enable the Automatic option of a data field. This will automatically add the data field to the Actions page, and add Set and Clear actions at the Inspection End Action point.

2. In the DataToPLC data table, once you have enabled the Automatic option, set the value to send for the selected field (of the correct data type) in the Value text box.

Alternatively, you can write to the DataToPLC data table using a ProfinetWriter step or an EthernetIPWriter step. The procedure for both PROFINET and EtherNet/IP is the same, to do so:

1. Add a writer step to the flowchart, or select it if you already have one added.

2. Click on the Manage Fields button in the Configuration pane to open the Platform Configuration dialog. Ensure that the DataToPLC page is selected, from there you can add or edit data fields in the DataToPLC data table.

3. In the Configuration pane, enable the data field to which the step should write. To specify a linked or advanced value, click on the right-arrow button and select the appropriate option, or you can drag and drop a link from the Quick Watch flyout panel or the Quick Evaluate pane.

To receive application-specific data from the PLC, you read from the DataFromPLC data tables using the ProfinetReader step or EthernetIPReader step. Data in the DataFromPLC data table will be the data that the PLC has written to the table during its last write cycle. The procedure for reading from both PROFINET and EtherNet/IP is the same, to do so:

1. Add a Readers step, or select it if you already have one added.

2. Click on the Manage Fields button in the Configuration pane to open the Platform Configuration dialog. Ensure that the DataFromPLC page is selected, from there you can add or edit data fields in the DataFromPLC data table.

   The value of a data field in the DataFromPLC data table is accessible using the outputs of the ProfinetReader step and EthernetIPReader step. Use the value element to access the data (For example, ProfinetReader.Fields("SerialNumber").Value).