Connection To The Rs-485 Interface - NAVTELECOM SMART S-2422 Operation Manual

The digital interface RS-485 is designed to connect devices transmitting and receiving information via this interface,
for example, fuel level sensors, CAN bus adapter, RFID.
As a rule, the interface is used to connect up to 6 digital fuel sensors. It is supposed to use digital LLS-compatible
sensors.
The RS-485 + interface line of the device should be connected to the RS-485 + line of the sensor, usually designated
as "A", and the RS-485 line of the device should be connected to the RS-485 line of the sensor, usually designated as "B".
The RS-485 interface specifications practically do not limit the length of cables on a land vehicle (100m or more), since the
interface is a differential bus and is well protected from the influence of external interference.
In the fuel sensor, the periodic data output mode must be turned off, and the network address and data transfer rate
must match the corresponding programmed parameters in the device itself.

2.8 Connection to the RS-485 interface

Line A
FLS
RS485
Line B
Line A
FLS
RS485
Line B
Line A
FLS
RS485
Line B
Figure 38. Connection diagram of fuel level sensors by RS-485 interface
14 13 12 11 10 9 8
7 6 5 4 3 2 1
«GND»
Fuse
(1А)
«-»
«+»
Car battery