Parameter Description - Danfoss VLT 5000 Operating Instructions Manual

Parameters and data type structures

Parameter description

Parameters which are accessible through the parameter
number (PNU) have additional attributes that are a
component of the accompanying descriptive element.
Writing/reading of a parameter description occurs
through the PCV portion by means of the RC
commands 4/5 and the subindex of the desired
descriptive element (see accompanying diagram).
Characteristics
The "characteristics" subindex extends the definition of
the parameter description. The individual bits 9 to 15
have the values TRUE [1] or FALSE [0] (see table below).
Bit Meaning
15 Active parameter
14 Array
13 Parameter value resettable only
12 Factory setting of parameter changed
11 Text available
10 Additional text array available
9 No write access (read only)
8 Lower and upper limit. Standardization
and size attribute not relevant.
0-7 Data type of the parameter corresponds
to OD
The low byte (bit 0-7) indicates the data type of
the parameter (see following table).
NB!:
The "data type" for each parameter can
be found in the corresponding column in
the chapter parameter listing.
MG.90.G1.02 - VLT is a registered Danfoss trademark
VLT® 5000/ 5000 FLUX/ 6000 HVAC/
8000 AQUA PROFIBUS
Data types supported by the frequency converter
Data Object Short form
type
3 5 12
4 5 12
5 5
6 5 02
7 5 04
9 5
10 5
33 5 N2
35 5 V2
1) See following page for details
Example: Data type 5 = Unsigned 8
Size attribute
The size attribute is 2 bytes long.
Byte 1 incorporates the physical unit of measurement
(size index), byte 2 the conversion index .
NB!:
The "conversion index" for each parameter
can be found in the corresponding column
in the chapter parameter listing.
The "conversion index" produces the conversion
factor for each parameter.
Example:
Parameter Conversion index = -3 <=> (10E-3
205: Conversion factor: 0.001
15200 = 15.200 Hz
An except from the PROFIDRIVE profile with
respect to the assignment of the size index and
the conversion index to the physical size can
be found on the following page.
Standardized value
A linear value 0% = 0 (0h), 100% are 214 (4000h)
Data type
Range
Resolution
Length
Note: Two's complement notation
MSB is the first bit after the sign bit of the first byte.
Sign bit = 0 = positive number
Sign bit = 1 = negative number
Description
Integer 16
Integer 32
Unsigned 8
Unsigned 16
Unsigned 32
Visible string
Byte string
Standardization
1)
value (16 bit)
Bit sequence
N 2
-14
-200% ... 200% - 2
-14
2 = 0,0061%
2 bytes
19