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Programming
1.
Too low inertia will cause acceleration of the
load, which may be dangerous or prevent
successful Flying start. Use DC brake instead.
2.
If load is driven eg. by "windmilling", the unit
might trip due to overvoltage.
3
3
3.
Below 250 rpm the Flying start will not function.
446
Switching pattern
Value:
60° AVM (60° AVM)
SFAVM (SFAVM)
Function:
Description of choice:
Normally it is not necessary for the customer to set this
parameter.
455
Frequency range monitor
Value:
Disable
Enable
Function:
his parameter is used if warning 35 Out of frequency range
must be turned off in the display in process control closed
loop. This parameter does not affect the extended status
word.
Description of choice:
Select [1] Enable [1] to enable the readout in the display if
warning 35 Out of frequency range occurs. Select [0] Disable
to disable the readout in the display if warning 35 out of
frequency range occurs.
461
Feedback conversion
Value:
Linear (LINEAR)
Square root (SQUARE ROOT)
Function:
In this parameter, a function is selected which converts a
connected feedback signal from the process to a feedback
value that equals the square root of the connected signal.
This is used, e.g. where regulation of a flow (volume) is
required on the basis of pressure as feedback signal (flow
= constant x √pressure). This conversion makes it possible
to set the reference in such a way that there is a linear
connection between the reference and the flow required.
See Illustration 3.25.
Description of choice:
If [0] Linear [0] is selected, the feedback signal and the
feedback value will be proportional.
If [1] Square root [1] is selected, the frequency converter
translates the feedback signal to be the square root value.
60
®
VLT
DriveMotor FCM Series
Illustration 3.25 Feedback Conversion
[0]
[1]
3.6.1 Serial Bus
Illustration 3.26 Serial Bus
[0]
[1]
3.6.2 Telegram Communication
Control and reply telegrams
The telegram communication in a master/slave System is
controlled by the master. A maximum of 31 slaves (FC
motors) can be connected to one master, unless a repeater
is used - see Illustration 3.28 and Illustration 3.30.
The master continuously sends control telegrams
addressed to the slaves and awaits reply telegrams from
these. The response time of the slaves is maximum 50 ms.
Only a slave that has received a faultless telegram
[0]
addressed to that slave will respond by sending back the
[1]
telegram unchanged.
Broadcast
A master can send the same telegram at the same time to
all slaves connected to the bus. In such broadcast
communication, the control telegram broadcast bit of the
address bit has a value of 1 (see VLT address). Address bits
0-4 are not used.
Contents of a byte
Each transmitted sign begins with a start bit. Subsequently,
8 databits are transmitted. Each sign is given via a parity
bit set at "1" when there is an even parity (i.e. an even
number of binary 1's in the 8 databits and parity bits
together). The sign ends with a stop bit and thus consists
of a total of 11 bits.
®
MG03BA02 - VLT
is a registered Danfoss trademark
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