The Device Module implements the device OsiSense XGCS for Modbus TCP. This device is added under the Industrial Ethernet manager with the name selected within the Add Function From Template dialog box.
The device is preconfigured. The configuration includes the Read Status channel for the cyclic data exchange with the device. The repetition rate for the channel is selected with 50 ms.
Global Variable List - GVL_<name device module>
The Device Module implements a GVL. This GVL is added under the Application node within a folder with the name selected within the Add Function From Template dialog box. The GVL gets the same name as the folder and the device but with the prefix GVL_.
The GVL contains the variables which build the interface from the implemented program code to the application. The clear name of the GVL and the uniform naming of the variables facilitate a simple and structured implementation into the application.
Program - Prg_<name device module>
The Device Module implements a program. This program is added under the Application node within a folder with the name selected within the Add Function From Template dialog box. The program gets the same name as the folder and the device but with the prefix Prg_. Besides, the program-call is added automatically to the associated task.
There are several possibilities to operate an OsiSense XGCS smart antenna. One of these is the dynamic read/write operation which is realized with this Device Module. Dynamic read/write means that the smart antenna executes automatically read or write commands each time a new tag is detected in front of the antenna. The automatically executed read/write commands are defined in instruction blocks which are previously sent from the controller application to the smart antenna using the explicit messaging.
By monitoring the tag counter which is cyclically updated via the Modbus TCP IOScanner, it is detected if a tag has passed the smart antenna. If the tag counter is increased, the data block Read Table is read from the antenna using the explicit messaging. These data include the result of the execution of the instruction block and in case of read operation mode the read data from the tag.
In addition to the control of the read or write operation the following functions are provided by the program code:
oMonitoring and control of the Modbus TCP communication with the smart antenna
oReinitialization on demand or after reconnection of the Modbus TCP channel
oActivation of the sleep mode
oSelect between read or write operation mode
oSend data to the smart antenna which shall be written on the tag by the instruction block
The program is divided into several actions. These are described in the following table.
|
Name of the action |
Description |
|---|---|
|
A01_ComStat |
Processes the functions to monitoring and control of the Modbus TCP communication with the device. |
|
A02_Operation |
This action contains the program code to select the operation mode and to control and monitor the read and write operation executed by the smart antenna. |
NOTE: For monitoring the communication state of the device the channel ID of the configured Modbus TCP channel must be set as value for the variable GVL_<name device module>.c_uiChannelId. The channel ID is automatically generated when the device is added to the project and can be obtained through the Device Editor in the tab Modbus TCP Channel configuration.
Further information about the control logic is available inside the program in terms of comments.
