Communication with Citect over MODBUS TCP

Transcription

1 Applied Engineering Integration Note Communication with Citect over MODBUS TCP Overview This document explains how to set up communications between the DVT 600 Series and Citect (SCADA software package) using Modbus TCP protocol. This approach makes it easier to obtain information from multiple SoftSensors and multiple SmartImage Sensors. Citect collects information from the factory floor and distributes it to the upper layers of production and resource management; DVT s SmartImage Sensor is a powerful and sophisticated source of data. Integration of the two products is thus extremely useful. A simple communications example is described to illustrate the configuration steps required in both a Citect project and a DVT inspection product. The purpose of this document is to cover these basic steps only, providing a basis for the reader to integrate the two products. The reader should be able to implement this example with basic knowledge of Citect. Hardware Citect is designed to work in a networking environment. However, for the example that will be described here, it will run on a single computer and communicate with a DVT 600 through Ethernet TCP/IP. With FrameWork 1.4 SR2 DVT has added a Modbus TCP driver, refer to the FrameWork Modbus Driver document for details before reading this document. Software On the DVT side: 1. Set up a simple inspection. For this example we will measure the width and height of a part and count the number of edges in the vertical and horizontal directions.

2 2. The Script used to write the data into the DVT registers is: 3. Set inspections running and start configuring Citect. On the Citect Side: 1. Create a Citect project and name it ModbusDVT. 2. Inside Citect explorer go to the communications folder and create an I/O server and name it ModbusServer. 3. Next in the Citect Project editor under Communications choose Boards and create a board with the following settings: Set the Board type to TCPIP. 2

3 4. Next in the Citect Project editor under Communications choose Ports and configure a port, belonging to Board1 with the following settings : Notice the Special Options text box. Type I followed by the IP number assigned to the DVT system. Then type P followed by the TCP port number 502. This option directs the port to the correct TCP/IP connection. Finally the T indicates TCP protocol as opposed to UDP. 5. Next in the Citect Project editor under Communications choose IODevices. Create an I/O device with the Protocol MODNET. 6. Next in the Citect Project editor under Tags choose Variable Tags. Create numeric Memory Tags to hold the data and display it within a page. It is Important to note the values of the raw and engineering scales to make sure the SmartImage sensor result is within these limits; the user can adjust them. Note also that the address field contains the desired hardware Modbus address. This address must be coordinated with the DVT register indexes used in the Script Tool. It is also important to use Citect help to obtain information about their data types to choose a correct type for each value. Refer to the FrameWork Modbus Driver and the Modbus Monitor Application document for information on the mapping of DVT and Modbus registers. 3

4 7. The next step is to develop a page. Open the graphics builder and create a new page, using a normal template and standard style; name it page1_dvt. The number ###.### items are mapped to variable tags defined earlier. Each tag is reading data from each Soft Sensor as the Sript Tool places it in the DVT registers. Remember to save the page before compiling. Appearance of page: a. Configuration of tags ###. They are mapped to the variable tags defined earlier. 4

5 8. The final step is to compile the project. Citect automatically creates a front control page containing access buttons to Page1_DVT, hardware alarms and a shut down button. Press the Page1_DVT button and the values should update on the screen. Conclusion With this example it was seen how to bring data from several SoftSensors sensors on a DVT system to Citect memory tags over an Ethernet connection. While this is a simple operation it is easy to appreciate the potential benefits. An extra port (BOARD1_PORT2 with another IP address) may be defined to bring data from another 600 in a straightforward fashion. This approach requires no Cicode to read and parse ASCII data and thus presents a more efficient alternative to application development. 5