6
This protocol process is visualized on the Khepera radio turret only (see the Khep-
era radio turret user manual for more details).
The data encapsulation and transmission protocol add an important quantity of
information and time delay to simple data transmission. This ensures correct data trans-
mission and is therefore necessary. Due to the fact that the added information and time
delay is independent from the quantity of data, optimal results in data transmission speed
are achieved with data having a length of 16 bytes (max length of data in a message).
WARNING
: environmental conditions can drastically influence the transmission
quality. Distance of transmission and quantity of data lost depend on several factors:
proximity of metallic structures, other radio devices and noise emission from computers
can all cause interferences. In a good environment no data should be lost. If data is lost,
please check the environmental conditions.
5
C
ONNECTIONS
This configuration allows the communication between the robot and a host compu-
ter through the radio link. On the host computer side the link is made by a RS232 line
and the radio base station. On the Khepera robot the link is supported by the radio turret.
The Khepera robot has to be set in a SerCom mode and be equipped with a radio turret.
The radio turret switch number 6 has to be set ON to support radio transmission as main
communication channel (COM). An ID has to be selected for each radio turret which will
be used on the network. For first tests, set the turret ID to 1. The test settings are illustrated
by figure 5.
Figure 5: Settings of the radio turret for the communication test.
For the radio base station, the following connections must be made:
• Between the radio base station and the host computer by a standard RS232
cable. This cable is not in the package because there are several standards
at the level of the host connector. You can easily find this cable by your host
computer dealer.
• Between the radio base station and the power supply with the cable fixed to
the power supply.
OFF
1 2 3 4 5 6 7 8
Turret ID: 1 used as main
communication channel
