MG.90.A2.02 – VLT is a registered Danfoss trademark
24
FCM 300 PROFIBUS / VLT 2800 PROFIBUS
DP
PCD
PCD
PCD
PCD
PCD
CTW according to Profidrive profile:
Control words consisting of 16 bits, the meaning of
the various bits appears from the table, page 22.
The following bit pattern sets all necessary start
commands: 0000 0100 0111 1111 = 047F Hex.*
0000 0100 0111 1110 = 047E Hex.*
0000 0100 0111 1111 = 047F Hex.
Quickstop:
0000 0100 0110 1111 = 046F Hex.
Stop:
0000 0100 0011 1111 = 043F Hex.
* Only necessary at power up.
MRV:
Speed reference, the data format is "Standardized
value", see page 19. 0 Hex = 0% and 4000 Hex =
100%.
In the example 2000 Hex is used corresponding to
50% of maximum frequency (parameter 202).
The whole PPO therefore gets the following value in
Hex:
Byte
Value
PCA
1
30
PCA
2
CF
IND
3
00
PCV
IND
4
00
PVA
5
00
PVA
6
00
PVA
7
03
PVA
8
E8
CTW
9
04
PCD
CTW
10
7F
MRV
11
20
MRV
12
00
The Process data within the PCD part is acting on the
VLT immediately, and can be updated from the
master as quickly as possible.
The PCV part is a “hand shake” procedure which
means that the VLT has to acknowledge the
command, before a new one can be written.
-
A positive response of the above example may
look like this:
Byte
Value
PCA
1
20
PCA
2
CF
IND
3
00
PCV
IND
4
00
PVA
5
00
PVA
6
00
PVA
7
03
PVA
8
E8
STW
9
0F
PCD
STW
10
07
MAV
11
20
MAV
12
00
The PCD part responds according to the state and
parametration of the VLT.
The PCV part responds as:
PCA: As the request telegram, but here the RC part is
taken from the response table on page 16. In this
example RC is 2Hex, which is a confirmation that a
parameter value of the type long word (32 bit) has
been transferred.
IND is not used in this example.
PVA: 03E8Hex in the PVA part tells that the value of
the parameter in question (207) is 1000 which
corresponds to 10.00.
STW: 0F07 Hex means that the motor is running and
there are no warnings or faults (for details see Status
word table on page 22).
MAV: 2000 Hex tells that the output frequency is 50%
of max. frequency.
