S N V 0 1 8 E C . X X
U S E R & I N S T A L L A T I O N M A N U A L
V 3 . 1
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proper transmition not possible. Fail-safe biasing is used to keep the receiver’s
output in a defined state when in idle state, avoiding
any noise interaction. Bias resistors consist of a pull-up
resistor on the non-inverting line A and a pull-down on
the inverting line B, maintaining a voltage difference
between them greater than 200mV (in order to have a
defined state). These resistors should be calculated
depending the terminal resistors, and placed on the
transmission line as illustrated in figure 15 (for “line
topology” having two terminal resistors).
Resistors is suggested to be metal film >= 0.5W.
For example using cable RE-2Y(St)Yv 04X2X0.5, 2
terminal resistors of 82 Ohm should be used at any
transmission line end. And bias resistors of 270 Ohm
when having two terminal resistors.
Figure 15: Bus termination
and Bias resistors
Summary of Contents for SNV018EC.XX
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