User guide

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6651-2211
About the automatic data rate detection
ODW-710-F2 automatically detects the data rate by monitoring incoming PROFIBUS data
frames on both the electrical and optical interfaces. When the data rate has been estab-
lished the BA LED will go active.
If no data frames are transmitted for a period of time the automatic data rate detection
will restart and the BA LED will go inactive.
The idle time before the automatic data rate detection restarts is set using DIP-switches
S2:4 and S2:5. The factory default setting is 5 seconds.
The automatic data rate detection determines the actual data rate by listening for
PROFIBUS Start Delimiters (SD1 – SD4) at the beginning of each data frame. If one or
more Start Delimiters are lost the automatic data rate detection will rest start.
The number of lost Start Delimiters before the automatic data rate detection restarts
is set using DIP-switches S1:2 and S2:6 – S2: 8. The factory default setting is 31 faulty
frames (31 lost Start Delimiters).
Note: Start Delimiters can be lost during an electrical or optical disturbance.
For example a PROFIBUS slave unit is connected/disconnected or an optical fibre is
disconnected. It is advisable to start of by using the factory default settings and only
manipulate them if a problem exists.