ELGO Electronic LIMAX2 Series Operating Manual page 33

10.4.3 Command Descriptions
Important:
Before you send a new message to the LIMAX2 wait for the answer first. After allocating a new address the
LIMAX2 answers in max. 0.5 seconds. In other cases it even in a few milliseconds. After this time it is not
expected to get an answer (transmission error).
10.4.3.1 Principle Format of Message
To LIMAX2
STX Byte
02h 1
STX
ETX
Check Byte
The meaning of bytes 1 to 4 can be found in the following chapters.
10.4.3.2 Position request of LIMAX2 with the address "i"
To LIMAX2
STX
02h 04h
04h = characterises the message as position request
i = address of the LIMAX2 (0Bh – 7Fh) to request
Position values are always smaller than FFFF00h
10.4.3.3 A LIMAX2 address request
Attach in each case only one LIMAX2 e.g. over a RS422/RS232 converter to the serial interface (COM-port) of a
PC.
To LIMAX2
STX
02h 05h
05h = characterizes a message as address request
i = LIMAX2 address
FFh FFh does not occur immediately after STX with position inquires as answer!
In this case (0Bh <= i <= 7Fh) this is the answer of the address request.
10.4.3.4 Allocation of an LIMAX2 address
Attach in each case only one LIMAX2 e.g. over a RS422/RS232 converter to the serial interface (COM-port) of a
PC.
To LIMAX2
STX
06h
02h
06h = characterizes a message as address allocation
i = the new LIMAX2 address. Important: At the answer you get the new address + 80h.
The addresses 80 h – FFh as well as 00 h – 0 Ah are FORBIDDEN. If you try to assign an address smaller than
eight, LIMAX2 gives you a "negative answer" and keeps its former address.
Byte Byte ETX
2 check 03h
= starts a message
= ends a message
= contains the arithmetic checksum of STX, byte 1 and byte 2.
Byte ETX
i check 03h
Byte ETX
05h check 03h
Byte ETX
i
check 03h
answer
STX Byte
02h 1
answer
STX MSB
02h xxh
answer
STX
02h FFh
answer
STX
02h FFh
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Connections and Interfaces
Byte Byte Byte
2 3 4
LSB Adr.
xxh xxh i
ABS-Position
i ETX
FFh xxh 03h
i + ETX
FFh 80h 03h