Danfoss 5000 Flux Manual page 25

MRV (Main Reference Value)
Speed reference value, the data format is "stan-
dardized value".
0Hex = 0% and 4000Hex = 100%.
For example, 2000Hex correspond to 50% of the
maximum frequency (parameter 202).
The entire PPO being sent from the master to the
VLT thus has the following hexadecimal values:
Byte
PCA 1 and 2
PCV I N D 3 and 4
PVA 5 and 6
PVA 7 and 8
PCD CTW 9 and 10
MR V 11 and 12
The process data within the PCD portion have a
direct effect on the VLT and can be updated by
the master in the quickest possible way.
The PCV portion is a process with an exchange of
acknowledgements (so-called handshake), i.e. the
VLT must confirm the command before a new one
can be written.
A positive response of the VLT to the above
example might look like this:
Byte
PCA 1 and 2
PCV I N D 3 and 4
PVA 5 and 6
PVA 7 and 8
PCD STW 9 and 10
MAV 11 and 12
The response of the PCD portion depends on the
status and the parameterization of the VLT.
The PCV portion responds as follows:
PCA
like the request telegram, but with the RC portion
assuming the characteristics for "transmit double
word" (HEX 2 for the RC portion).
I N D
is not used in this example.
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PVA
03E8Hex in the low-byte of the PVA portion indi-
cates that the value of the parameter in question
(207) is 1000, which corresponds to 10.00.
The high-byte portion of the PVA is HEX 0000.
STW
0F07Hex means that the motor is running and that
no warnings or errors are present (further details
can be found in the status word table).
Value MAV
2000Hex indicates that the output frequency is
30CF
50% of the maximum frequency.
0000
0000
A negative response of the VLT might look like this:
03E8
047F
2000
PCV
PCD
RC is HEX 7 which means that the request is not
executable. The corresponding error number is in
the low-byte portion of the PVA.
In this case, the error number 2 means that the
upper or lower warning limit of the parameter has
Value been passed (see table of error numbers in "PCA
processing").
20CF
0000
0000
03E8
0F07
2000
Byte Value
PCA 1 and 2 70CF
I N D 3 and 4 0000
PVA 5 and 6 0000
PVA 7 and 8 0002
STW 9 and 10 0F07
MAV 11 and 12 2000
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