Siemens SINAMICS S120 - Page 125

Communication via PROFIBUS
Acyclic communication
4-125
E Siemens AG, 2004. All rights reserved
SINAMICS S120 Installation and Start-Up Manual, 12/04 Edition
Description of fields in DPV1 parameter request and response
Table 4-16 Description of fields
Field
Data type Values Comments
Request reference Unsigned8 0x01 ... 0xFF
Unique identification of the request/response pair for the master. The master
changes the request reference with each new request. The slave mirrors the
request reference in its response.
Request ID Unsigned8 0x01
0x02
Read request
Write request
Specifies the type of request.
In the case of a write request, the changes are made in a volatile memory (RAM).
A save operation is needed in order to transfer the data to the non-volatile
memory (p0971, p0977).
Response ID Unsigned8 0x01
0x02
0x81
0x82
Read request (+)
Write request (+)
Read request (–)
Write request (–)
Mirrors the request identifier and specifies whether request execution was
positive or negative.
Negative means:
Cannot execute part or all of request.
The error values are transferred instead of the values for each subresponse.
Axis Unsigned8 0x00 ... 0xFF Number
Addresses an axis on a multi-axis drive. Different axes with separate parameter
number ranges can be accessed over the same DPV1 connection.
No. of parameters Unsigned8 0x01 ... 0x27 No. 1 ... 39
Limited by DPV1 telegram length
Defines the number of adjoining areas for the parameter address and/or
parameter value for multi-parameter requests.
The number of parameters = 1 for single requests.
Attribute Unsigned8 0x10
0x20
0x30
Value
Description (not implemented)
Text (not implemented)
Type of object accessed.
No. of elements Unsigned8 0x00
0x01 ... 0x75
Special function
No. 1 ... 117
Limited by DPV1 telegram length
Number of array elements accessed.
Parameter number Unsigned16 0x0001 ... 0xFFFF No. 1 ... 65535
Addresses the parameter to be accessed.