B&B Electronics LDVDSV2-S-P9D - Manual - Manual (Page 23)

OBDII Streamer Command & Response
V2.11
Page 23/49
0x21 – ENABLE_PARAMETERS
Description:
This command will enable or disable only the specified parameters to be updated from
the vehicle. If parameters are enabled that are not supported by the vehicle the OBDII
Streamer will send a response indicating which parameters are not supported.
By default all supported parameters are enabled and queried from the vehicle. Because
the update rate of the vehicle is limited to a maximum of 20 Hz, it may be desirable to
disable some parameters to get better update rates on parameters of interest.
Command to Send:
0x01 0x01 0x21 DL RD/WR ENABLE/DISABLE PARAMETER_LIST CS
Response to write:
0x01 0x01 0xA1 DL 0x01 ENABLE/DISABLE NOT_SUPP CS
Response to read:
0x01 0x01 0xA1 DL 0x00 PARAMETER_LIST CS
Field Description:
DL
Data Length Byte
RD/WR
This indicates if the message will be a read or a write.
0x00 = read
0x01 = write
Note: If the request message is a configuration read then
the ENABLE/DISABLE and PARAMETER_LIST fields
should not be included, and the data length will be 1 byte.
ENABLE/DISABLE
This field in 1 byte that indicates if the parameters specified
in PARAMETER_LIST should be enabled or disabled.
The state of the parameters not specified in the
PARAMETER_LIST field will not change.
0x00 = Enable specified parameters
0x01 = Disable specified parameters
This field will not be present in a response to a read
enabled parameters command.
PARAMETER_LIST
Variable length data field containing one byte for each
parameter to be enabled. Each byte corresponds to a
parameter ID. This should not be included in the request
message if reading the ENABLE_PARAMETERS data.