Siemens SIMOTRAS 6SG7050, Руководство по эксплуатации

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Start-up 01.04
7-52
SIEMENS AG 6SG7000-0BA76
SIMOTRAS HD Operating Instructions
7.10.7 Structure of request/response telegrams
There is no basic difference between the useful data area in the request and response telegrams
for PROFIBUS and CAN Bus. There are differences, for example, in the protocol frame and in the
sequence in which H and L bytes are transmitted. The structures shown here are those of a
SIMOTRAS HD, i.e. the values are displayed in the same way as they would be for parameters
n733 and n735, for example. The structure of the protocol frame and the transmission sequence of
bytes are therefore described where necessary in the sections containing the start-up description
for the appropriate board.
Each request and each response basically comprises three areas apart from the telegram frame
with header and trailer:
Header
Trailer
Index
IND Parameter value
PWE Parameter identifier
PKE
The parameter identifier (PKE) contains a request or response identifier (i.e. type of request or
response) and the number of the addressed parameter. The spontaneous signaling bit SPM (bit11)
is not used on the SIMOTRAS HD master.
Header Trailer
Index
IND
SPM
Parameter value
PWE Parameter identifier
PKE
Task/ response
identifier
Parameter number (PNU)
Bits 0 to 10 contain the number of the parameter specified in the request.
Owing to the length restriction of the bit field (11 bits), a
parameter number
(PNU) higher than
1999 must be converted to another code for use in the parameter identifier; the Page Select Bit in
the index is used for this purpose:
Parameter
area
Displayed
number
Input on OP1S PNU in parameter
identifier
Page Select Bit
(index bit 15)
P xxx, r xxx
0 - 999 0 - 999 0
Basic unit
U
xxx,
n
xxx 2000 - 2999 0 - 999 1
H xxx, d xxx
1000 - 1999 1000 - 1999 0 Technology
board
L xxx, c xxx 3000 - 3999 1000 - 1999 1
In the case of a request, for example, which specifies parameter U280 (2280), therefore, PNU =
280 must be entered in the parameter identifier and bit 15 set in the index.