B&B Electronics LDVDSV2-S-P9D - Manual - Manual (Page 6)

OBDII Streamer Command & Response
V2.11
Page 6/49
Overview
The OBDII Streamer is an OBDII to Serial gateway. The raw data, multiple PIDs per
parameter, and timing issues of the OBDII bus are abstracted from the host. The OBDII
Streamer allows a developer to quickly access data from the vehicle without having
knowledge of the OBDII bus.
The OBDII Streamer is intended to be permanently installed in a vehicle. Coupled with
B&B Electronics OBDII Y-Cable the OBDII Streamer will immediately disconnect from
the OBDII bus when another scan tool is connected to the bus.
The maximum update rate of data from the OBDII bus is 20Hz. Each parameter enabled
constitutes one update from the vehicle. The update rate from the vehicle is not linked to
any messages from the host. The host will be able to request data from the OBDII
Streamer immediately after the previous response, but the OBDII data will be limited to
an update rate of 20Hz.
Vehicle status parameters, such as the MIL, Fuel Level, and Battery Voltage, will be
updated from the vehicle no faster than once every 2 seconds. The vehicle parameter
DTC’s will be updated from the vehicle no faster than once every minute. The host can
request these parameters from the OBDII Streamer at any rate desired.
Startup Procedure
When the OBDII Streamer is powered on a CRC check will be performed to verify that
the code on the device is valid. This will take approximately 10 seconds and during that
time the device is unable to respond to commands.
On initial power on the OBDII Streamer will attempt to detect the vehicle type and
supported parameters. This process can take up to 1 minute. During this time the OBDII
Streamer will be responsive to host requests. If the OBDII Streamer has detected a
vehicle type and supported parameters it will not attempt to detect them again, even if the
vehicle type and supported parameters have changed.
While the host is detecting the vehicle’s information most messages will be responded to
with the following response.
0x01 0x01 0x81 0x00 0x83
//Vehicle Not (Yet) Detected Message