For the operation of the BIS VU read heads on a BIS V evaluation unit, Balluff has created its own module to simplify protocol handling for the commissioning engineer.

The module can be used for both electromagnetic BIS VU heads and inductive BIS heads.

First, the BIS V is connected to a PC via the USB interface (communication line BCC0CR2) and connected via the UHF Manager software.

Individual parameters of the respective VU heads can be set in the software. As each application is universal, the parameters must be adjusted individually.

You can find a suitable function block for the respective product in the download area on the Balluff homepage.

After downloading, the function block is inserted into the project via the "Extras" tab.

The function block should now be available in the library:

The function block can now be inserted into the program using drag and drop.

An instance DB must also be created for this:

As soon as the function block is available in the network, the variables used can be linked.

Their assignment can be found in the variable table:

Attention:

The HW_LADDR corresponds to the hardware address of the read head, which can be found in the system constants:

Transmit, receive and a MultiEPC data block are required for data transmission. A DB is created for each of these:

Attention:

The data blocks must not have optimized block access. For this purpose, the optimized block access must be deselected in the "Attributes" properties:

Once all variables have been linked accordingly, the program can be loaded into the controller.

The module does not output a CT signal for UHF systems, as this system only reacts to active commands.

For a read command, "Command" must be set to 81hex.

The command is triggered via Start:

The read data is stored in the "Receive" DB:

The DB was created as an array so that the data is displayed correctly.

The function block confirms the successful read with "Ready"

First, the data to be written must be defined in DB_Send:

For a write command, "Command" must be set to 82hex.

The command is triggered via Start:

The module confirms successful writing with "Ready"

The read command is restarted for verification.

The written data is now available in the "Receive" DB:

With UHF systems, it is possible to read several data carriers at once and the multiple read command can differentiate between EPC and TID.

To do this, a selection must be made on the module:

If the input is "0", the EPC is read; if "1", the TID is read.

A data block with the following structure must be created for this:

Read EPC:

The 47hex command is set. The data block contains the following data:

2 data carriers were recognized. The respective EPCs are written to the data block.