B&B Electronics HVD100A3 Benutzerhandbuch

2 

HDV100A3 Command & Response Manual-1306cr 

B&B Electronics -- 707 Dayton Rd. -- PO Box 1040 -- Ottawa, IL 61350 

PH (815) 433-5100 -- FAX (815) 433-5104

 

Intelligent Mode Command Protocol 
 
The HDV100A3 uses a simple protocol to communicate to vehicle bus. The 
protocol is divided into four parts:   

Start Of Frame (SOF) 
Control Field (shown in light gray) 
Data Field (shown in dark gray) 
Checksum (CS) 

 
 

 SOF 

Number of 

Control Bytes 

Control Bytes 

Number of 
Data Bytes 

Data Bytes 

CS 

1 byte 

1 byte 

1 to 20 bytes 

1 byte 

1 to 100 bytes  1 byte 

 

The Start of Frame byte is the first byte in a valid frame and is 

always 01 hex. 
 

The Control Field sets up the function and control of the 

HDV100A3 hardware and is formatted as shown below. 
 
 

Number of Control 
Bytes to Follow 

ID Byte 

Function 
Byte 

Control Data Bytes 

1 byte 

1 byte 

1 byte 

Up to 20 bytes 

 
The first byte of the Control Field is the number of control bytes in 

the message. This value indicates the number of control bytes, excluding 
itself, to follow. If the message doesn’t contain any control bytes, the 
Number of Control Bytes value will be set to 00 hex as a placeholder.  

The next part of the message frame is the data field. The data field 

is preceded by the number of data bytes, excluding itself, to follow and is set 
to 00 hex if no data is present in the message. The data field is reserved for 
data that is to be communicated to the vehicle bus.  
 
 

Data Field Structure 

Number of 
Data Bytes 

 Data Bytes 

1 byte 

 Up to 100 bytes 

 

The last element of a valid message is the checksum. The checksum 

is calculated by adding ALL bytes from the Start of Frame (inclusive) to the 
last data byte and using the last 8 bits as a checksum.