Using SystecCAN Plugin

The SystecCAN plugin encapsulates the low-level API to work with the SYS TEC CAN 适配器。

This plugin requires the SYS TEC CAN device drivers and the usbcan32.dll (usbcan64.dll for 64 bit builds).

创建 CAN 总线设备

At first it is necessary to check that QCanBus provides the desired plugin:

if (QCanBus::instance()->plugins().contains(QStringLiteral("systeccan"))) {
    // plugin available
}

Where systeccan 是插件名称。

Next, a connection to a specific interface can be established:

QString errorString;
QCanBusDevice *device = QCanBus::instance()->createDevice(
    QStringLiteral("systeccan"), QStringLiteral("can0.0"), &errorString);
if (!device) {
    // Error handling goes here
    qDebug << errorString;
} else {
    device->connectDevice();
}

Where, can0.0 is the active CAN interface name (interface 0, channel 0). The SystecCAN plugin supports 64 USB interfaces (so called modules) from can0.0 to can63.1 . Each module can have one or two channels, they can be accessed by the index canX.0 or canX.1. The availableDevices() method returns a list of currently available devices.

注意： SYS TEC also provides 8 or 16 channel CAN interfaces. These units consist of an USB hub and multiple two-channel modules internally.

The device is now open for writing and reading CAN frames:

QCanBusFrame frame;
frame.setFrameId(8);
QByteArray payload("A36E");
frame.setPayload(payload);
device->writeFrame(frame);

The reading can be done using the readFrame() 方法。 framesReceived() signal is emitted when at least one new frame is available for reading:

QCanBusFrame frame = device->readFrame();

SystecCAN supports the following configurations that can be controlled through setConfigurationParameter() :

配置参数键	描述
QCanBusDevice::BitRateKey	Determines the bit rate of the CAN bus connection. The following bit rates are supported: 10000, 20000, 50000, 100000, 125000, 250000, 500000, 800000, and 1000000. Note that this configuration parameter can only be adjusted while the QCanBusDevice is not connected.
QCanBusDevice::ReceiveOwnKey	The reception of CAN frames on the same channel that was sending the CAN frame is disabled by default. If this option is enabled, the therefore received frames are marked with QCanBusFrame::hasLocalEcho ()