Page 84
TITANUS
PRO·SENS
®
TECHNICAL MANUAL
5.4
Installation of the reset board
The reset board can be installed into TITANUS
PRO·SENS
®
as an option. If
several TITANUS
PRO·SENS
®
are connected to one detection line the reset
board is only installed to the last TITANUS
PRO·SENS
®
on the detection line.
The electrical connection of the reset board is made according to the
connection diagram in chapter 5.6.3.
The reset board can only be used if the quiescent current of the detection
line is between 5 mA and 50 mA and if the end of the detection line is an
ohm-resistor.
Quiescent current
of the line
The quiescent current I
R
of the line is calculated as follows:
I
U
R
R
L
E
=
where
R
E
= original end-of-line resistor in
Ω
U
L
= line voltage in V
I
R
= quiescent current of the line in [A]
The formulae to calculate the end-of-line resistor and the quiescent current of
the detection line consider the ideal state of the signal evaluation.
If acknowledgement is not possible by means of the calculated end of line
resistor of the reset board the value of the end-of-line resistor is reduced by
about 20%.
End-of-line resistor
The reset board replaces the detection line resistor. It is re-calculated and
installed on the reset board (connector X1). The value of the end-of-line
resistor R
ER
is calculated as follows:
(
)
R
U
V
I
ER
L
R
=
−
2 7
,
where
R
ER
=
end-of-line resistor on the reset board in
Ω
U
L
=
line voltage in V
I
R
=
quiescent current of the line in [A]
INSTRUCTION
