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VL
VL
T 2800 : : : : :
T 2800
T 2800
VL T 2800
VL
VL
T 2800
The bus termination
See drawing on page 6
It is essential that the bus line be terminated properly.
A mismatch of impedance may result in reflections on
the line that will corrupt data transmission.
-
The PROFIBUS is provided with a suitable
termination which may be activated by the
switches of the RS485 switch block located
just to the left of the terminal block X100 (see
drawing below). The switches should be on to
terminate the bus.
The switches should never be left in opposite
positions. They should either both be ON or
both be OFF!
MG.90.A2.02 – VLT is a registered Danfoss trademark
FCM 300 PROFIBUS / VLT 2800 PROFIBUS
-
Most masters and repeaters are equipped with
their own termination.
-
If an external termination circuit consisting of three
resistors is connected to the bus line a 5 V d.c.
power supply must be used, please note that this
must be galvanically isolated from the a.c. line.
11
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