Baumer VeriSens ID Series Technical Documentation Manual page 298

This protocol has a defined format:
Element Size
{ / [
1 byte
( / <
Length 4 or 8 bytes ASCII-
Hex
Device number 2 byte ASCII hex
Command 2 byte
Parameters 4-12 bytes
Data variable
Checksum 2 byte ASCII hex
} / ]
1 byte
) / >
The following section is used to calculate the checksum:
If you use the RS485 bus protocol (device number: 6), the formats change as follows:
v2.11.0-B4
Meaning
These codes are used for synchronization of the transfer.
If you specify the length in 4 bytes, use the code "{" (datagram
with checksum) or "[" (datagram without checksum).
If you specify the length in 8 bytes, use the code ")"(datagram
with checksum) or ">" (datagram without checksum).
The length is equivalent to the number of transferred bytes
from the device number (inclusive) to the end of the data, i.e.
without any checksum.
If the datagram exceeds a length of 65,535 bytes and you
require 8 bytes for the length, you must use the start code "(" or
"<".
Each connected device has its own device number in a range
from 1 („01")-254 („FE"). Number 0 is reserved to address the
bus master (PLC, PC ...).
Device number 255 ("FF") can be used to send commands to
all connected devices simultaneously.
Command designation
Each command has a parameter block at least 4 bytes in
length, some of which remain unused.
Optional data section, which may contain result or job data.
The checksum is produced by linking all characters beginning
with the device number to the end of the data byte for byte with
XOR.
The checksum must only be specified if the start code "{" or " ("
is used, otherwise this entry is omitted.
These codes are used as the end codes of the command
blocks.
If you specify the length in 4 bytes, use the code "}" (datagram
with checksum) or "]" (datagram without checksum).
If you specify the length in 8 bytes, use the code ")"(datagram
with checksum) or ">" (datagram without checksum).
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VeriSens
Baumer Optronic GmbH
Radeberg, Germany
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