Previous

Next

Function RTUEndpointInterval

RTUEndpointInterval determines the polling frequency for periodic (Interrupt and Isochronous) endpoints:

int RTUEndpointInterval(RTUDeviceHandle               Device, 
                        const RTUEndpointDescriptor * Endpoint);

Parameters

Device

Device handle passed to an attachment/detachment callback.

Endpoint

Pointer to an endpoint descriptor belonging to the Device returned by RTUGetEndpoint.

return value

Number of frames (1 millisecond) or microframes (125 microseconds) for High-Speed and faster devices between polls.

When transactions are pending on the given endpoint, RTUSB-32 will query the endpoint with the frequency returned by this function. Interrupt endpoints can NAK the query and return no data. Isochronous endpoints will always return data, though it can be less than the maximum packet size returned by RTUEndpointPacketSize.

Note that the returned unit is frames for Low- and Full-Speed devices, but microframes for High-Speed, SuperSpeed, and SuperSpeedPlus devices.

This function returns 0 for non-periodic endpoints.

Device Query

Function RTUEndpointPacketSize

Function RTUFindEndpoint