Download 3 Programming the Handheld Terminal

Serial Gateway Coupling
Protocol
Serial Side (KeTop -> Gateway)
Structure of Telegrams
Request Telegram
The request telegrams always have a length of 11 bytes. They consist of:
z
3 bytes of control characters (STX, ETX, BCC) and
z
8 bytes of MMI-COM data (2 bytes header und 6 bytes data part)
The first byte contains the handshake information between the handheld
terminal and the PLC.
The second byte in the header contains the index number which stands for
a certain command. The structure of the data fields (user data) is defined
by the corresponding index.
11 bytes request telegram
8 bytes MMI-COM data
2 bytes Header
Byte 1
Byte 2
STX
Handshake
Byte 3
Byte 4
6 bytes data
Byte 5
Byte 6
Byte 7
Byte 8
ETX
BCC
Index
Control character:
STX ... Start transfer
ETX ... End transfer
BCC ... Block check character
The description of the request telegram in the chapters "HT System Variables“ and "HT Functions" only refers to the MMI-COM data part without control characters.
User's Manual, version: 1.1 / material no.: 62010
© KEBA 2005
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