Balluff
RFID reader settings
For smooth communication between controller and RFID readers, some settings need to be made before the system startup. These include, for example, the baud rate for the serial communication. A proprietary tool from the manufacturer of the RFID reader may be required in order to transfer these settings to the RFID.
For all supported RFID reader models, the following standard data transfer settings have been tried and tested:
Setting | Value |
|---|---|
Baud rate (RS232 and RS485) | 9600 baud |
Parity Bit | none |
Data bits | 8 |
Stop bits | 1 |
Depending on the hardware, other parameters can also be set, or the factory settings of the RFID reader can be used. These must then also be adopted in the software reader connection (see RFID reader connection).
Using the proprietary tools, the following special settings must be parameterized before starting the system:
Setting | Value |
|---|---|
Data transmission parameters (see above) | Setting analogous to the values selected in the PLC program |
Type of protocol - telegram end identifier | LF CR |
Data carrier type | All types (or setting according to needs) |
Send CT data immediately | deactivated (or activated – however, no evaluation takes place) |
Dynamic operation | deactivated |
Send power-on message | deactivated (or activated – however, no evaluation takes place) |
CRC16 data check | deactivated |
Type and serial number with CT pres. | deactivated (or activated, as required) |
If Type and serial number with CT pres. is enabled, the RFID reader automatically sends the transponder type and its serial number as soon as a transponder is detected. If a command is sent immediately after the detection of a transponder and receipt of this set message, then the correct attribution of the type of the following response and an associated evaluation cannot be guaranteed. It is advisable to manually query existing transponders using the GetInventory command. Otherwise at least a short waiting period should be adhered to before sending the command and the structure should be subjected to a test cycle.
If the RFID reader is set up so that telegrams are sent automatically from the reader to the controller (for example, on detection of a transponder by Type and serial number with CT pres.), then the following must be observed:
The end identifier (LF CR) is used in this case as a suffix for the recognition of telegrams. Previous data are combined into a telegram as soon as these 2 bytes are detected in the data stream. This may lead to an error and failure to evaluate the telegram. If it is possible for the end identifier to be present within the data in automatically sent telegrams, then a data query must be selected by means of a command call instead of the automatic transmission. The telegrams are recognized reliably as a result of this measure.
RFID reader handling
The function blocks of the library support communication from Balluff readers to transponders with 4-8 bytes serial number.
If Balluff RFID readers are used, the serial number of 13.56 Mhz transponders is rotated byte-by-byte by the library function block. This takes place because the serial number read out from a transponder would otherwise not correspond to the serial number read out on another reader. This allows devices from different manufacturers to be operated together in the same network.
When using a Balluff BIS-L60x0:
- The variable iDCType = 0 must be set (see input structure stCtrl).
- When the GetInventory command is called, information from both read heads is returned via the serial interface. However, only the information from the read head selected by stCtrl.iHeadNumber is evaluated and output at the stTranspInfo output.
- If Type and serial number with CT pres. is enabled, the RFID reader automatically sends the transponder type and its serial number as soon as a transponder is detected. By default, this only affects the first read head. Switching to the second read head is not directly supported by the library. Furthermore, the number of the read head on which the tag was recognized cannot be assigned (iHeadNumber = 0).
It must be pointed out here that not all peculiarities of every supported RFID reader model can be named here. For detailed information, please refer to the manufacturer's own documentation.