Data transmission
lines A and B connected
correctly?
Error
Cause
Correction
No data exchange
possible, only one of the
control LEDs (red =
transmit
green = receive) on the
side of the device lights
up
Lines exchanged, or
loose contacts on the
device terminal blocks!
Is the baud rate (Profibus)
set correctly for all
devices?
Error
Cause
Correction
Transmission error
The baud rates are
either set falsely or not
at all!
Notice: If no baud rate
is activated, the levels of
the data signal shift.
Check the DIP switch
settings on all devices,
(see Chapter 7.3)
Notice: Line length for
9.6 - 93.75 kbit/s up to
1.2 km,
187.5 kbit/s up to 600 m,
500 kbit/s up to 200 m
Are the terminating
resistors correctly switched?
(Profibus only)
Error
Cause
Correction
Transmission error
The terminating
resistors are incorrectly
switched!
Notice: Devices must
only be terminated at
the beginning and end
of a line!
Check DIP switch
settings on all devices,
DIP switches must both
either be set to 0 or to 1
(see Chapter 7.3)
Notice: if necessary
measure the line
terminations directly in
the bus line (switch off
mains). If the
termination is
considerably less than
110 Ohm, the data
signal level deteriorates,
harmonics are possibly
occurring on the B-line
at 0 signal.
Leuze electronic
DDLS 170
43
