VB3i MANUAL
Page | 14
22 May 2014
RS232 serial / CAN
VBOX3i is equipped with 2 CAN Bus interfaces and 2 RS232 serial ports. The primary RS232 port is used for all
communication between the VBOX and laptop PC. The primary port is marked RS232 on the VBOX3i front panel. The
primary RS232 port is able to transmit live data from the VBOX to the PC for viewing and performing real-time tests. It
is important to note however that due to limitations of the PC serial port, live data transfer of all channels is limited to
20Hz, at 50Hz only standard GPS channels should be transmitted, and at 100Hz only Sats, Time, Speed, and Trigger
Event Time should be transmitted. Logging too many channels at too high a rate is likely to cause drop-outs and loss of
data.
Therefore for maximum accuracy, tests performed at a GPS sample rate above 20Hz should be logged to compact
flash and post processed.
The secondary RS232 port is used for connection to a Telemetry Radio module allowing the reception of Differential
GPS (DGPS) data for local correction from a Racelogic Local DGPS basestation. The secondary RS232 port is located in
the connector marked CAN on the VBOX3i front panel.
The CAN Bus ports A and B are located in the VBOX3i connectors “CAN” and “RS232” respectively. The function of
these ports is configurable by the user for use by either Racelogic external modules or the users own CAN Bus
equipment. For dual use of RS232 and CAN from one of the sockets you will require a 5Way Lemo splitter
RLVBACS024.
Power supplied to external Racelogic CAN modules through the “CAN” or “RS232” cables is at the same voltage as
the input power supply. Therefore when using Racelogic external CAN modules (eg; MFD or ADC03), the VBOX3i
supply voltage must not exceed 15vDC.
