Siemens SIMOVERT MASTERDRIVES Manual page 247

02.2004
Telegram structure
Data coding
Siemens AG 6SE7087-6QX70 (Version AD)
SIMOVERT MASTERDRIVES
SIMOVERT SIMOVERT
MASTERDRIVES MASTERDRIVES
"Slave"
Fig. 8.1-1 Serial linking of SIMOREG/SIMOVERT drive converter (slaves) with a
higher-level computer as the master
Each telegram begins with the start character STX (= 02 hex), followed
by the length information (LGE) and the address byte (ADR). The net
characters then follow. The telegram is terminated by the BCC (Block
Check Character).
STX LGE ADR
Fig. 8.1-2 Telegram structure
For single-word data (16 bit) in the net data block (= net character
block), the high byte (first character) is always sent and then the low
byte (second character). The same applies to double-word data: the
high word is sent first followed by the low word.
The protocol does not identify tasks in the net characters. The contents
of the net data for SIMOVERT MASTERDRIVES drive converters is
dealt with in Section 8.1.3.
Information is coded as follows:
♦ STX (start of text)
ASCII characters: 02 hexadecimal
♦ LGE (telegram length)
1 byte, contains the telegram length
♦ ADR (address byte)
1 byte, contains the slave address and the telegram type
(binary coded)
♦ Net characters
Each one byte, contents are task-dependent
♦ BCC
1 byte, Block Check Character
Compendium Motion Control
Higher-level
computer
"Master"
SIMOVERT
MASTERDRIVES
"Slave" "Slave"
1. 2.
Net characters
Communication / USS
SIMOVERT
MASTERDRIVES
"Slave"
n BCC
8.1-3