VLT® 5000/ 5000 FLUX/ 6000 HVAC/
8000 AQUA PROFIBUS
■
PCA processing
The master controls and monitors frequency converter
parameters through the PCA portion of the PPOs
type 1, 2 and 5 and requests a response from
the frequency converter (slave). In addition to the
parameter processing, the frequency converter can
also transmit a spontaneous message.
Requests and responses
involve an acknowledgement
exchange (a so-called handshake) which cannot be
worked off in stack operation. This means that the
master, when sending a read/write request, must wait
for the response before sending a new request. A
request or response is limited to a maximum of 4
bytes, i.e. no text strings can be transmitted.
PCA - Parameter description
15 14 13 12
11
10
9
8
7
6
5
4
3 2 1
0
RC
MSP
PNU
RC:
Request/Response
Characteristics
(Sector: 0-15)
SPM: Toggle bit for spontaneous
messages
PNU: Parameter Number
(Sector: 1-990)
Request and response
In the RC portion of the PCA word the requests of the
master to the slave are triggered. The other two PCV
fields IND and PVA must be evaluated as well.
The PVA portion transmits parameter values in
word size with the bytes 7 and 8; double words
require the bytes 5-8, i.e. 32 bits.
If the request or response contains array elements,
the array subindex will be in IND (byte 3). In
the event of a parameter description, IND
contains the record subindex.
RC content
Request
Function
0
No request
1
Request parameter value
2
Change parameter value (word)
3
Change parameter value (double word)
4
Request description element
5
Change description element
6
Request parameter value (array)
7
Change parameter value (array word)
8
Change parameter value (array double
word)
9
Request number of array elements
10-15
Not assigned
Re-
sponse
Function
0
No response
1
Transmit parameter value (word)
2
Transmit parameter value (double
word)
3
Transmit description element
4
Transmit parameter value (array word)
5
Transmit parameter value (array double
word)
6
Transmit number of array elements
7
Request not executable (with error
number, see below)
8
No operating authority for PCV
interface
9
Spontaneous message (word)
10
Spontaneous message (double word)
11
Spontaneous message (array word)
12
Spontaneous message (array double
word)
13-15
Not assigned
If a request from the master is not executed by the
slave, the RC word in the PPO-Read has the value 7.
The error number is in bytes 7 and 8 of the PVA element.
Error no.
Meaning
0
1
Parameter value not changeable
2
Upper or lower value passed
3
Faulty subindex
4
No array
5
Wrong data type
6
Setting not permitted (resettable only)
7
Description element not changeable
8
No PPO-Write for IR
9
Description data not available
10
Access group
11
No parameter operating authority
12
Keyword missing
13
Text not readable in cyclical traffic
14
Name not readable in cyclical traffic
15
Text array not available
16
PPO-Write missing
17
Request temporarily unexecutable
18
Other error
19
Data not readable in cyclical traffic
MG.90.G1.02 - VLT is a registered Danfoss trademark
18
Содержание VLT 5000 Series
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