Liebherr MKv 3910 - Manual (Page 12)

24
Terminating resistor
When connecting several appliances
via the RS485 interface, the terminat-
ing resistor must remain on the last
appliance.
Remove the terminating resistors
from the appliances in between.
External alarm
We recommend connecting the appliance
to an external alarm device.
There are various connection options at
the back of the appliance.
The appliance may only be connected
to an external alarm device by trained
personnel.
Floating alarm
output
Connection to
RS485 interface
Note
The connectors are secured with
screws. To remove the connectors,
undo the left and right screws.
RS485 interface
Rx- / Tx-
Send/Receive data cable (negative
pole)
Rx+ / Tx+
Send/Receive data cable (positive
pole)
GND
Earth cable
N.O
Alarm output
Connection for a visual warning light or
an acoustic alarm signal.
N.C
Operating light
Connection for a control lamp to indicate
that the appliance is in normal mode.
COM
External power supply unit
42 V/8 A DC maximum
Minimum current: 150 mA
Floating alarm output
These three contacts can be used to connect the appliance to
an optical or acoustic alarm device.
The connection is designed for a maximum of 42 V/8 A DC from
a safety extra-low voltage (SELV) source (minimum current:
150 mA).
Important
When supplying mains voltage to the floating alarm contact,
the technical safety requirements of standard EN 60335
will not be satisfied.