Attributes

ARINC 429 parameters such as bus speed, inter-word gap, word parity, and others can be read or modified using the mxfAttributeUint64Get(), mxfAttributeDoubleGet(), mxfAttributeUint64Set() and mxfAttributeDoubleSet() functions by 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 to get 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 example code below shows how to initialize an ARINC 429 transmitter channel and set some of the transmission parameters like the bit-rate, parity, and word gap.

MXF_ATTRIBUTE_INFO_UINT64_DETAILS info;      // Attribute detail structure
HMXF_CHANNEL channel;                        // Channel handle
uint64 speed;
uint32 rc;

     ...

    // Obtains infos on speed attribute
    if(!rc)
        rc = mxfAttributeInfoDetailsGet(channel, KMXF_A429_SPEED, &info);

    // Gets the default speed set
    if (!rc)
    {
        rc = mxfAttributeUint64Get(channel, KMXF_A429_SPEED, &speed);
        printf("Channel speed = %llu bps\n", speed);
    }

    if (!rc)
    {
        printf("Channel speed min=%lld, speed max=%lld\n", info.details.range.min, info.details.range.max);

        // Sets the channel speed to maximum speed, parity odd, inter word gap value default 4-bit
        rc = mxfAttributeUint64Set(channel, KMXF_A429_SPEED, info.details.range.max);

        if(!rc)
           rc = mxfAttributeUint64Set(channel, KMXF_A429_PARITY, VMXF_A429_PARITY_ODD);

        if(!rc)
           rc = mxfAttributeUint64Set(channel, KMXF_A429_GAP, 16);
    }

    ...