Mechanisms For Processing Parameters Via The Profibus - Siemens 6RA7086-6KS22 Operating Instructions Manual

Start-Up
A total of five PPO types are defined:
PKW section
PKE
st
1
word
PPO1
PPO2
PPO3
PPO4
PPO5
PKW: Parameter ID value
PZD: Process data
PKE: Parameter identifier
The acyclic channel MSCY_C2 (see diagram above) is used exclusively for the start-up and
servicing of DriveMonitor.
7.7.2.1

Mechanisms for processing parameters via the PROFIBUS:

The PKW mechanism (with PPO types 1, 2 and 5 and for the two acyclic channels MSAC_C1 and
MSAC_C2) can be used to read and write parameters. A parameter request job is sent to the drive
for this purpose. When the job has been executed, the drive sends back a response. Until it
receives this response, the master must not issue any new requests, i.e. any job with different
contents, but must repeat the old job.
The parameter section in the telegram always contains at least 4 words:
Parameter identifier
Details about the telegram structure can be found in Section 7.7.9, "Structure of request/response
telegrams", and in the PROFIBUS profile "PROFIBUS Profile, Drive technology" of the user's
organization PROFIBUS International (http://www.profibus.com).
The parameter identifier PKE contains the number of the relevant parameter and an identifier
which determines the action to be taken (e.g. "read value").
The index IND contains the number of the relevant index value (equals 0 in the case of
nonindexed parameters). The IND structure differs depending on the communication mode:
Definition in the PPOs (structure of IND with cyclical communication via PPOs)
-
Definition for acyclical channels MSAC_C1 and MSAC_C2 (structure of IND with acyclical
-
communication)
The array subindex (referred to simply as "subindex" in the PROFIBUS profile) is an 8-bit value
which is transferred in the high-order byte (bits 8 to 15) of the index (IND) when data are
transferred cyclically via PPOs. The low-order byte (bits 0 to 7) is not defined in the DVA profile.
The low-order byte of the index word is used in the PPO of CBP2 to select the correct number
range (bit7 = Page Select bit) in the case of parameter numbers of > 1999.
In the case of acyclical data traffic (MSAC_C1, MSAC_C2) the number of the index is transferred
in the low-order byte (bits 0 to 7). Bit 15 in the high-order byte is used as the Page Select bit. This
assignment complies with the USS specification.
Index value 255 (request applies to all index values) is meaningful only for acyclical transmission
via MSAC_C1. The maximum data block length is 206 bytes with this transmission mode.
7-24
IND PWE PZD1
STW
1
ZSW
1
nd rd th st
2 3 4 1
word word word word
IND:
PWE: Parameter value
STW: Control word
Index
PKE IND
PZD section
PZD2 PZD3 PZD4 PZD5 PZD6 PZD7 PZD8 PZD9
HSW
HIW
nd rd th th
2 3 4 5
word word word word
Index
Parameter value 1
PWE1 (H word)
th th th
6 7 8
word word word
ZSW Status word
HSW: Main setpoint
ISW: Main actual value
Paramter value 2
PWE2 (L word)
SIEMENS AG
SIMOREG DC Master Operating Instructions
05.05
PZD
10
th th
9 10
word word
6RX1700-0AD76