Attributes

CAN bus parameters such as bus speed and bus state can be read or modified using specific CAN bus functions:

• mxfCanBusTimingSet() / mxfCanBusTimingGet()
• mxfCanBusStateSet() / mxfCanBusStateGet()

Other attributes, like FIFO aging timeout or threshold can be read or modified using the mxfAttributeUint64Get(), mxfAttributeDoubleGet(), mxfAttributeUint64Set() and mxfAttributeDoubleSet() functions, passing the handle (device, module or channel) and attribute key-value pair.

See the section Attributes Reference for a description of all supported attributes.

Some other utility functions are used for getting more information about attributes;

• mxfAttributeInfoGet()

  Returns the name, type and property of an attribute.

• mxfAttributeInfoDetailsGet()

  Gets the scope of an attribute; min/max values, resolution.

• mxfAttributeListGet()

  Returns the attribute list of the specified handle (device, module or channel).

• mxfAttributeCountGet()

  Returns the number of attributes related to a specific handle (device, module or channel).

The following code shows how to configure an CAN channel speed at 500Kbps and enabled it.

{
HMXF_SERVER server;                          // Server handle
HMXF_DEVICE device;                          // Device handle
HMXF_MODULE module;                          // Module handle
HMXF_CHANNEL channel;                        // Channel handle
uint64 deviceIdx = 0;                        // Device index #0
uint64 moduleType = MXF_MODULE_CANBUS;       // CAN module
uint64 moduleCount;
uint32 rc;
MXF_CANBUS_TIMING timing;                    // CAN timing

   //Connects to the server
   rc=mxfServerConnect("0.0.0.0", "", "", 0, &server);

   //MXF initialization
   if (!rc)
      rc = mxfSystemInit(server);

   //Obtains the first device handle
   if(!rc)
      rc = mxfSystemDeviceGet(server, deviceIdx, &device);

   //Obtains the first module handle
   if(!rc)
      rc = mxfDeviceModuleAllGet(device, moduleType, 1, &moduleCount, &module);

   //Obtains first channel handle
   if(!rc && moduleCount)
      rc = mxfModuleChannelGet(module, 0, &channel);

   //Sets the channel speed to 500Kbps with sampling point at 75%
   if(!rc)
   {
      timing.options = 0;     // reserved
      timing.sjw = 1;         // sync each bit
      timing.sampTriple = 0;  // sample once each bit
      timing.brp = 4;         // prescaler (clock 64MHz)
      timing.tseg1 = 11;      // quanta before sampling point
      timing.tseg2 = 4;       // quanta after sampling point
      rc = mxfCanBusTimingSet(channel, &timing);
   }

   //Sets the bus state to enabled
   if(!rc)
      rc = mxfCanBusStateSet(channel, TRUE);
}