Pcv Parameter Access - Danfoss VLT PROFIBUS DP MCA 101 Programming Manual

Parameter Access
5.2.20 Supported data types
Value
3
4
5
6
7
9
10
33
35
44
54
5 5
Table 5.12 Supported Data Types
5.2.21 Value
The value field contains the parameter value of the
request. When the response is negative, the field contains
a corresponding error code. If the values consist of an odd
number of bytes, a zero byte is appended to maintain the
word structure of the telegrams.
For a positive partial response, the parameter value field
contains the following attributes:
Format=Data type or byte, word, double word
Number of values=Actual number of values
Value=Parameter value
For a negative partial response, the parameter value field
contains the following:
Format=Error (44H)
Number of values=1
Value=Error value=Error number
5.2.22 Error Codes for Drive Profile V3.0
When the parameter request is invalid, the frequency
converter returns a corresponding error code. Table 5.13
lists the full range of error codes.
Error Meaning
code
0x00 Unknown parameter
0x01 Parameter is read-only.
0x02 Value out of range due to maximum/minimum
value.
0x03 Wrong sub-index
0x04 Parameter is no array.
0x05 Wrong data type (wrong data length)
0x06 This parameter may not be set, only reset.
0x07 Descriptive element is read-only.
0x09 No description available (only value).
0x0b Process control not possible.
0x0f No text array available (only value).
0x11 Not possible in current state.
0x14 Value out of range due to drive state/configu-
ration.
0x15 Reply too long (more than 240 bytes).
28
Data type
Integer16
Integer32
Unsigned8
Unsigned16
Unsigned32
Visible string
Octet string (byte string)
N2 (standardised value)
V2 (bit sequence)
Error
Time difference without date indication
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Programming Guide
Error
code
0x16
0x17
0x18
0x65
0x66
0x67
0x68
Table 5.13 Error Codes for DP-V1 Parameter Requests

5.3 PCV Parameter Access

The PROFINET cyclical data exchange performs parameter
access via the PCV channel. The PCV channel forms part of
the PPOs described in chapter 4 Control.
Use the PCV channel to read and write parameter values,
and read status for descriptive attributes of each
parameter.
5.3.1 PCA Handling
The PCA part of PPO types 1, 2 and 5 performs several
tasks. Using PCA, the master controls and supervises
parameters, and requests a response from the follower.
Then the follower responds to a request from the master.
Requests and responses is a handshake procedure and
cannot be batched. Therefore, when the master sends out
a read/write request, it must wait for the response before
it sends a new request. The request or response data value
is limited to maximum 4 bytes (see RC characteristics in
Table 5.14), which implies that text strings are not
transferable. For further information, see
chapter 7 Application Examples.
5.3.2 PCA - Parameter Characteristics
15 14 13 12
Additional
RC
Info
0
Table 5.14 PCA - Parameter Characteristics
sub-index
sub-index
RC: Request/response characteristics (Range 0..15)
sub-index
SMP: Spontaneous message (Not supported)
0
PNU : Parameter no. (Range 1..1999)
0
sub-index
sub-index
5.3.3 Request/Response Handling
0
0
0
The RC portion of the PCA word defines:
0
•
sub-index
0
•
Meaning
Wrong parameter address (unknown or
unsupported value for attribute, element,
parameter number or sub-index or illegal
combination)
Illegal format (for writing)
Value amount not consistent
Wrong axis: action not possible with this axis
Unknown service request
This service is not possible with multi parameter
access
Parameter value can not be read from bus.
11 10 9 8 7 6
SMP
The requests issued from the master to the
follower.
Other portions of the PCV involved:
Additional
Info
0
0
0
-
-
-
-
5 4 3 2 1 0
PNU
MG37G102