Bourgogne ET Grasset SAS VEGRDE2 Manual De Usuario

Vegas Long Range Read/Write Device 

 

27-07-2002 

Vegrde3/EG 

Confidentiality Level 1 

Page 8 (48) 

Bourgogne et Grasset  -– ZI Beaune Savigny  -– 21200 Beaune  –  France  –  Tel. +33 380 26 26 26  –  Fax. +33 3 80 26 26 00 

 

⇔ HOST 

The device communicates with the host (processor, PC, ...) via serial interface using a baud rate 
of 9600 baud. Data transfer details are: 1 start bit, 8 data bits, 1 stop bit and no parity bit, Least 
Significant Byte is sent first. 
 

 
The individual blocks show a common structure. Each block starts with the block length, 
followed by a block title (function number or status) and then the data. The data are transmitted 
transparently, i.e. you can use any character between 0x00 and 0xFF. Finally there is a check 
sum which is formed as EXOR - link of all transferred data. 
 
General Data Transfer Format: 
 

Function  block length block title / status 

data 

data 

......... 

check sum 

 
Block length is the sum of all transferred bytes including block length but excluding check sum. 
The check sum is calculated by bytes 1 to n-1. 
Data bytes only are transmitted if data is transferred. 
 
Transfer timeout intervals are defined as follows: 
 
a) 

 

Character delay is the maximum time permitted to elapse between sending two consecutive 
characters of a block. 
 
  

≤ 150 ms 

 
 
b) Block 

 

There must be a minimum interval  - defined as block delay - between two blocks sent, to 
allow for re-synchronization in case of  malfunction. 
 
  

≥ 160 ms 

 
This block delay is only necessary if an error has occurred in the serial communication.