Siemens simovert masterdrives, Справочник

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Communication / USS 02.2004
6SE7087-6QX70 (Version AD) Siemens AG
8.1-12
Compendium Motion Control SIMOVERT MASTERDRIVES
1
st
word 2
nd
word 3
rd
word 4
th
word (m+2) word
PKE IND PWE1 PWE2
• • •
PWEm
With:
♦
1 word
≤
m
≤
110 words (maximum) when 16 PZD words
(maximum) are contained in the net data block.
♦
1 word
≤
m
≤
126 words (maximum) when there is no PZD.
Telegram data transfer with variable telegram length means that the
slave responds to a telegram from the master with a telegram whose
length does not have to be the same length as the telegram from the
master to the slave. The length of elements PEW 1 to PWE m in the
reply telegram and what is contained in them depends on the task
issued by the master. Variable length means that only the number of
words necessary to pass on the appropriate information is transferred.
The minimum length, however. is always 3 words.
If a slave, for example, transfers a parameter value which is a 16-bit
quantity (e.g. the output voltage in parameter r003), then only 3 words
of the PKW area are sent in the telegram from the slave to the master.
With regard to the MASTERDRIVES MC/VC for example, if the current
speed (parameter r002) is to be read, the PKW area in the telegram
from the slave to the master is 4 words long since the speed is stored
as a 32-bit quantity in parameter r002. Variable word-length
parameterization is mandatory if, for example, all values are to be read
at once from an "indexed" parameter or if the parameter description of
a parameter is to be partially or completely read. This setting to variable
word-length is made during start-up.
Do not use a variable word length if a SIMATIC S5 or SIMATIC S7 is
the master.
PKW area
parameterized with
variable word length
NOTICE