FCM 300 / FCD 300 / VLT
®
2800 / DP V1 PROFIBUS
The Profibus
Interface
The bus termination
68 = RxD/TxD-P
∼
(red cable)
69 = RxD/TxD-N
∼
(green cable)
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 on the bottom
of the electronics part (see drawing below). The
switches should be on to terminate the bus.
-
Most masters and repeaters are equipped
with their own termination.
NB!:
The switches should never be left in opposite
positions. They should either both be
ON or both be OFF!
NB!:
Is 126 or 127 selected the address is setting
via P918, refer to chapter station address.
-
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.
MG.90.A5.02 - VLT is a registered Danfoss trademark
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