Westermo ODW-641 - Manual (Page 11)

11 6650-2291
Functional description
Converter PROFIBUS DP – optical fibre
ODW-641 is a fibre optic modem that converts between electrical PROFIBUS DP and a
fibre optical link.
Repeater – optical fibre links
ODW-641 is a fibre optic repeater that repeats received data from one fibre link out to
the other link. This is useful e.g. for long distance communication, where electromagnetic
interference may occur or when isolation of the electrical network is needed. The maxi-
mum optical fibre distance depends on selected fibre transceiver and fibre type.
Distances up to 80 km (50 miles) are available.
Data rate up to 12 Mbit/s
ODW-641 converts PROFIBUS DP data using data rates from 9 600 bit/s up to
12 Mbit/s. Retiming of the PROFIBUS DP data ensures that the correct signal form is
transmitted from the ODW-641 converter.
Automatic data rate detection
The PROFIBUS data rate is set automatically as soon as the ODW-641 receives a correct
data frame, whether data is received from PROFIBUS DP or the fibre optic link.
The detected data rate remains until a number of consecutive faulty received frames have
been detected or no further frames are detected within the timeout period. The timeout
period is set by switches, with the default setting of 31 faulty frames or 5 seconds with-
out any received frames.
Internal Electronics
COM
COM
+VA
O
V
P +VB
C
NO
NC
STATUS
POWER
LED’s
O
V
P
O
C
P
RxD/TxD - P
RxD/TxD - N
SHIELD
PROFIBUS DP
CH 1
SFP
Fibre transceiver
TX
RX
Switches
OVP Over Voltage Protection
OCP Over Current Protection