How to Use the CAN-USB Terminal

The CAN-USB terminal offers a GUI to facilitate communication between PC and CAN board via USB. The picture shows the user-interface of the CAN-USB terminal. Its purpose is to instruct the CAN board to send CAN-messages with a specified Message ID, but it is also possible to switch the LEDs on the board on and off (checkboxes in circle 7).

Figure 1.19: USB Driver Installation Final Step

At first it is necessary to choose a port to be connected with by selecting it in the “Portname”-combobox in circle 1. When the program is started, it searches for accessible COM-Ports automatically. If the board is connected to the PC after the terminal is started, the COM-port has to be searched manually by clicking the “get Ports”-button (1). It can be useful to search the port names manually when the name of the used port is unknown. By comparing the list in the “Portname”- combobox before and after clicking the “get Ports”-button, the needed port name will be found easily. The next step is to define the baud rate for the CAN-bus. By default it is set to 125 kbps, but rates between 10 kbps and 1 Mbps are available. It is important that every member of the bus uses the same baud rate. Now the port can be opened by clicking on the “open”-button. The CAN-Bus will be initialized automatically with the chosen baud rate. When the port is opened the label on the button will change to “close”. There are two lists (8) to log the transmitted and received messages and to log events like opening and closing the port. After opening the port successfully it will be logged in the left list. In the list on the right side the acknowledge- ment from the microcontroller that CAN is initialized is noted. The “received message”-list also logs every CAN-message the controller receives. By default the CAN-message-ID is set to 123456 (in HEX). To change it the “CAN-message-ID”-textbox (4) has to be changed. To send the desired CAN-message, it simply has to be entered in the “Message”- textbox. After this is done either the “send”-button (6) can be clicked or the RETURN-key on the keyboard can be pressed. The message will be logged in the right list. NOTE: the message has to be hexadecimal (!) and the maximum length is 8 bytes. To check the correct functioning of the connection, there are three checkboxes (7) to switch the LEDs (red, green, yellow) on.