MG.90.D1.02 – VLT is a registered Danfoss trademark
24
VLT
®
5000/5000 Flux/6000 HVAC/8000 AQUA PROFIBUS
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Examples
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Example 1: PCV portion and control word /
reference value
Example for the application of type 1 PPOs to
modify the ramp rise build-up time (parameter 207)
to 10 s and to trigger a start and a speed control of
50% (parameter 512: FC profile = factory setting).
NB!
Modified parameters are only stored perma-
nently (protected against a mains failure) in
the EEProm of the VLT if parameter 971 is trig-
gered after the parameter modification.
PPO, Parameter Process Data Object
PCD
Process Data
PCV
Parameter Characteristics Value
PCA
Parameter Characteristics (bytes 1, 2)
PCA processing see below
I N D
Subindex (byte 3), (byte 4 not utilized)
PVA
Parameter Value (bytes 5 to 8)
CTW
Control Word
STW
Status Word
M R V
Main Reference Value
MAV
Main Actual Value
PCV
PCA Parameter characteristics
RC:
Request/Response Characteristics
(Range: 0-15)
SPM: Toggle bit for spontaneous messages
PNU: Parameter Number
(Range: 1-990)
PCA portion (byte 1-2)
The RC portion determines what the PCV portion is
to be used for.
If a parameter needs to be changed, value 2 or 3
must be selected; here, 3 was selected since pa-
rameter 207 refers to a double word (32 bits).
SPM bit
In the example, the function
“spontaneous mes-
sages”
is not needed (parameter 917 = OFF) and
thus the SPM bit is set to 0.
PNU = Parameter Number
The parameter number is set to: 207 = CF Hex.
This means that the value for the entire PCA por-
tion is 30CF Hex.
IND (bytes 3-4)
This is used in reading/changing of parameters
with subindex, e.g. in the case of parameter 915. In
the example, the bytes 3 and 4 are set to 00Hex.
PVA (bytes 5-8)
Changing the data value of parameter 207 to
10.00 s. The transmitted value must be 1000, since
the conversion index for parameter 207 is -2, i.e.
the value received by the VLT is divided by 100 so
that the VLT ”understands” 1000 as 10.00. 1000
corresponds to 03E8Hex.
PCD (Process Data)
CTW (Control Word)
The following bit patterns set all necessary start
commands:
15 ....
...0 <=> Bit number
0 000 0100 0111 111 1 <=> 047FHex.
15 14 13 12
11
10
9 8 7 6 5 4 3 2 1 0
R C
SPM
PNU
Examples