Datalogic DS2 Ethernet - COMMUNICATION PROTOCOL; Packet Description

DS2 Ethernet Instruction Manual
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7. AREAscan
TM
DS2 SERIES – COMMUNICATION PROTOCOL
7.1. Packet description
As mentioned, the communication protocol requires the presence of a client unit and of a master unit.
The communication type is Ethernet.
The exchange of information is made in the request-reply mode: the client sends a data frame to the
master that replies sending another data frame to the client.
7.1.1 Binary data packet structure
A binary data packet is composed of a group of bytes placed in a well-defined sequence, that
identifies it univocally. It presents a heading, body and an end.
The heading and the end have a fixed length while the body has a variable length.
Packet start
Length
Type
Data
Packet end
Checksum
 Packet beginning: 1 byte, STX ASCII code (‘0x02’)
 Length: 1 byte, length in bytes of the Type field plus the Data field
 Type: 1 byte, code identifying the packet type ( ‘A’, ‘B’, ‘C’ ASCII code, etc.)
 Data: variable number of bytes (from 0 to 254) that form the packet information
 Packet end: 1 byte, ETX ASCII code(‘0x03’)
 Checksum: 1 byte, complement to one of the Length, Type and
Data field bytes sum.
7.1.2. Short protocol binary data packet structure
There is a binary data packet with reduced protocol composed by one byte. This format is reserved
to trasmission of numeric type value only (for example one measure).
Data
Data: 1 byte with binary data packet
7.1.3. ASCII data packet structure
An ASCII data packet is composed of:
Packet start
Type
Data
Packet end
 Packet beginning: 1 byte, ‘*’ ASCII code (0x2A)
 Type: 1 byte, code identifying the packet type ( ‘A’, ‘B’, ‘C’ ASCII code, etc.)
 Data: variable number of ‘0’-‘9’ ‘A’-‘Z’ ASCII codes (from 0 to 254) that form the
packet information
 Packet end: 1 byte, CR ASCII code (0x0D)
Heading Body End
Body
Heading Body End