User's Manual

This document is the property of KYMATI GmbH and must not be copied or disclosed without its written authorisation.
© - KYMATI GmbH – 2020
KY.MAN.0105 (4.0) KY-LOC 1D.02.01 User Manual
Doc.- No.: KY.MAN.0105
Version: 4.0
Date: 17.05.2021
Page: 31 of 43
The CRC part with a size of 2 Bytes is described in the following table:
Name
Offset
Datatype
Description
CRC
0
Unsigned Integer (16 Bit)
CRCCCITT with
generator 0x1021 and
seed 0xFFFF
The CRC is computed on Header and the Content specific data field.
The CRC field is always at the end of a KYMATI Radar message.
The Content specific data field is determined by the “ContentType” Field of
the header part and can have a maximum size of 118 bytes.
When sending messages from a Host over Ethernet or RS-485 use the “HOST (0)” value for
the “Source Bus Identifier”. The “Destination Bus Identifier” field is ignored when
communicating through Ethernet. For RS-485 connections, however, this field is either the
actual bus identifier on the bus, or the special value 0xFF, which can be used to broadcast a
message to all devices simultaneously. Please note that there will be no response messages
for broadcasts to avoid message collisions on the RS-485 bus.
The following values for the source and destination routing identifiers are supported:
Routing Identifier Name
Value
Microcontroller
0
RS-485
1
Ethernet
2
When sending messages from a host over Ethernet to the device use the “Ethernet” value for
the “Source Routing Identifier“ field. Similarly, when sending messages from a Host over RS-
485 use the “RS-485” value. If this is not set correctly, the responses will be sent back through
the wrong connection.
When receiving messages from the device the corresponding source and destination fields will
be flipped.
In the case of an Ethernet connection, there is also an option to use a fixed size message
format for a more convenient use with PLCs. In that case, the content specific data field is
padded with additional zero bytes such that the messages are always 128 bytes in size,
including the header and CRC field. The CRC computation then also includes the additional
padding bytes.
For some commands, a series of messages needs to be exchanged between the host and
the device in a specific order. If the device does not get an expected message in a certain
amount of time, it will automatically abort the current command and will wait for a new
command.
7.1 Device Commands
The KYMATI Secondary Radar protocol currently supports the following content types: