Using LabView via the CANape COM Interface Version Application Note AN-IMC-1-036

Transcription

1 Version Application Note AN-IMC Author Restrictions Abstract Knoll, Steffen Public Document The Application Note shows how to create a client application in LabView using the CANape COM interface to access the ECU. Table of Contents 1 Overview Requirements Include the CANape COM Interface into the LabView environment Set up the communication between CANape and LabView Instantiation Initialization Attach an ECU device Set up a measurement in LabView Select an ECU measurement mode Selection of the ECU measurement signals Measurement start in LabView Receiving the measurement data Stopping the measurement Closing the measurement session Contacts...15

2 1 Overview The purpose of this application note is to create a client application in LabView using the CANape COM interface to access the ECU. This application note describes how to include the CANape COM interface in LabView, how to set up the communication with CANape and how to configure and start a measurement. The block diagram in Figure 1 shows the system setup of the interface between LabView and CANape and between CANape and the ECU. Figure 1: 1.1 Requirements This application note is based on LabView version 2014 and CANape 4.0 or higher. Both applications have to be installed on the computer. Since CANape 13.0 it is also possible to install the CANape COM interface on a second PC. In this case the CANape COM interface uses a TCP connection to CANape server. This application note describes the usage of the client interface on a local PC. After installation of CANape, the CANape COM interface is registered in the Microsoft windows registry. From now on CANape is ready to work as a COM Server. Copyright Vector Informatik GmbH 2

3 2 Include the CANape COM Interface into the LabView environment First create a new LabVIEW project. The LabVIEW project select dialog appears automatically after start of LabVIEW (Figure 2) Figure 2 After a new project is created, it is possible to select a project template. For this is example a blank project is used (Figure 3) Figure 3 Copyright Vector Informatik GmbH 3

4 Figure 4 After a new project is created, the project explorer shows an empty project without any VI file. (Figure 4) Figure 5 With a right click on the project root node, a new open a new VI file can be created an added to the project. (Figure 5 and Figure 6) Copyright Vector Informatik GmbH 4

5 Figure 6 The first step to get access to CANape COM in a LabView project the COM interface must be instantiated. Therefore, the LabView object Automation Refnum has to be selected (Figure 6). To select the requested automation interface, LabView offers the Select ActiveX Class\Browse function to select the CANape 1.9 Type Library in a dropdown box. (Figure 7) After this LabView displays a new icon in the Application window. This icon is also displayed in the Diagram window. With a right mouse click on the icon, CANape COM can be selected. (Figure 6 and 7) Figure 7 Copyright Vector Informatik GmbH 5

6 Per Drag&Drop the ActiveX-Refnum object has to be placed in the LabView Frontpanel page. Right click the icon with the mouse, select the ActiveX Class item and select the CANAPELib.IApplication from the pop up menu (see Figure 7). Figure 8 After selection of CANape COM interface the LabView icon changes to the view which is shown in Figure 9. CANAPELib.iApplication represents the root interface of the CANape COM application model. Figure 9 Copyright Vector Informatik GmbH 6

7 3 Set up the communication between CANape and LabView 3.1 Instantiation After the declaration of the CANape COM interface an object of this type needs to be instantiated. Therefore, the LabView object Open ActiveX-Object has to be selected via the popup menu of the CANAPELib.IApplication on LabView s Block diagram page (Figure 5). Figure 10 Figure 11 To use the CANape COM interface the output of the object CANAPELib.IApplication must be wired with the input of the Automation open object (Figure 12). LabView can now use the CANape COM interface methods and properties. At the end of a LabView session, the CANape COM automation interface must be closed. We will discuss this topic in a later section. Copyright Vector Informatik GmbH 7

8 3.2 Initialization Figure 12 To start and initialize CANape in the automation mode the Open method must be used. This method is delivered by the interface CANAPELib.IApplication. To include this method in LabView s block diagram the object Invoke Node must be used. This object has to be wired with the object Automation open (Figure 8) and the desired method Open can be selected via the popup menu (Figure 12). Figure 13 The method Open has two parameters. The first parameter describes the path to the working directory of CANape. The working directory must contain the ECU description file in the ASAP2 (*.a2l) file format. The second parameter is used as a debug flag. CANape will use the flag information to Copyright Vector Informatik GmbH 8

9 decide whether the CANape Write Window should be hidden or displayed. More information about the Write Window is available in the CANape manual. To get a clearer arrangement in this example the initialization sequence is placed into an own frame (Figure 16). This can be realized by using the Stacked Sequence element. In the LabView Frontpanel three String Input Elements have to be placed for specifying the Working Directory, the Device Name and the ECU s A2l file name. Add an on/off switch element for the debug flag. Connect in the Bock diagram the labeled String Input Element Working Directory to the workdir connector. Add a Boolean to (0:1) converter element in the Block diagram and connect it with the CANape debug element and to the debug connector (Figure 16 and 17). Figure 14 Figure 15 Copyright Vector Informatik GmbH 9

10 3.3 Attach an ECU device To attach the ECU to CANape additional information is needed from LabView. The used driver type e.g. CCP or XCP and the ECU description file (*.a2l) must be defined. Add a stacked sequence element and redo the same steps as previously described to add a CANAPELib.Devices instance. Add then the different elements as shown in Figure 11 and connect the previously defined String Input Elements to the interface connectors. Figure 16 The wire of IApplication is delivered by the previous frame (Figure 16). The first step is to read out the IDevices interface using the property IApplication.Devices. To attach a new device the method IDevices.Add has to be used. This method has four parameters. The first parameter describes the information about the device name. The second parameter describes the name and location of the *.a2l file. The third parameter defines the used protocol, e.g. CCP or XCP and the last parameter defines the CAN channel which is used to connect the ECU to CAN hardware. In this example, the Vector CCPsim ECU Simulator is used. Therefore, the driver CCP is used as DriverType and CAN channel 1 is defined as communication interface between CANape and the ECU. With these settings in LabView the CCPSim ECU simulator can be accessed by CANape. Copyright Vector Informatik GmbH 10

11 4 Set up a measurement in LabView 4.1 Select an ECU measurement mode In this example three measurement signals from the ECU will be measured in the polling mode. In the first step, the ECU Measurement mode must be selected. Depending on the ECU implementation several measurement modes are available and can be selected. Via the task ID the ECU measurement mode is selected. Therefore the CANAPELib.ITasks interface is needed. ITasks is a property of IDevice.ITasks and is designed to ask the ECU about the implemented tasks. In this example, the task with the ID 1 will be selected and this means that the polling measurement mode will be used. The selected task is delivered as an ITask interface. It is delivered as a return value of the method ITasks.item. Add a frame behind the new stacked sequence element and redo the same steps as previously described to add a CANAPELib.ITasks instance. Add and connect in the next steps the different elements as shown in Figure 19. Figure Selection of the ECU measurement signals To select the ECU measurement signals the client application (LabView) has to know their names. Because the CANape COM implementation is based on ASAP 3 V 2.1 functionality there is no possibility to ask the server for the object names defined in the ECU description file (ASAP2 file, *.a2l). (Figure 20) Copyright Vector Informatik GmbH 11

12 Figure 18 To declare the measurement objects the interface IChannels is needed. This interface is delivered by the property ITask.Channels. To add the measurement signals into the measurement signal list of CANape the method IChannels.Add must be used. This method has one parameter which describes the name of a measurement object (Figure 20). In the LabView front panel three String Input Elements needs to be placed for specifying the CCPSim channel1 to 3 (Figure 21). Figure 19 Copyright Vector Informatik GmbH 12

13 4.3 Measurement start in LabView Figure 20 To start the measurement in LabView the IMeasurement interface is required. IMeasurement is a property of the interface IApplication. The return parameter must be declared in LabView with a To G Data Object. (See section 3.3) The interface IMeasurement provides two methods: > IMeasurement.Start and > IMeasurement.Stop to stop the measurement again. To start a measurement the method IMeasurement.Start (Figure 22) is used. 4.4 Receiving the measurement data Figure 21 To receive measurement data the method ITask.NextSample is used. One way to call this method repeatedly, is to implement a while loop (Figure 23). If the calling frequency of this method is higher than the sampling rate the method will return with an error. A timer is included into the while loop to avoid this case. Copyright Vector Informatik GmbH 13

14 To get an output on the screen a LabView Array Object must be used (Figure 24). Additional the array must be filled with a Digital Indicator Object. To fill the object with the measurement results the object should be wired to the G Data Object. Figure Stopping the measurement Figure 23 To stop a measurement session the method IMeasurement.Stop should be called. This method is part of the IMeasurement interface. Copyright Vector Informatik GmbH 14

15 4.6 Closing the measurement session Figure 24 To close the VI sequence at the end, each COM interface has to be released in order of their dependency on each other. In this example, the release order has to be done in this way: > IMeasurement > IChannels > ITask > Itasks > IDevice > IDevices Before releasing the IApplication interface the method IApplication.Quit must be called. This method cleans the CANape internal interface and closes CANape at the end. It is impossible to get a new connection to CANape without calling this method (Figure 26). 5 Contacts For a full list with all Vector locations and addresses worldwide, please visit Copyright Vector Informatik GmbH 15