In the GPS element, there is a 2-byte speed. - this is speed based on GPS data, it is always included in the packet.
If I/O element "Speed" is enabled. In AVL data packets IO element with ID 24 is going to be included. It is a 2-byte I/O element - it is the same speed from GPS, just that it is included as IO element to have the possibility to create events for it.
There is a I/O element with ID 37. This is a 1 byte element - it is speed from OBDII data. It is wise to use this element as the base for correct speed readings, as GPS data sometimes might be not very accurate.
