6 Connecting OTT CBS
The OTT CBS has the following interfaces
䊳
SDI-12
䊳
4 … 20 mA (current loop)
䊳
RS-485, 2-wire (SDI-12 protocol via a physical RS-485 interface)
as well as a
䊳
connection for the power supply (U
Bat
+ GND).
The three interfaces make it possible to connect the OTT CBS both to OTT data-
loggers and to any datalogger by another manufacturer that has the correct inter-
faces. The SDI-12 interface meets SDI-12 Standard 1.3 (SDI-12 = Serial-Digital
Interface with 1200 baud).
All electrical connections are made using two screw terminal strips (supplied) at
terminal blocks A and B on the underside of the OTT CBS.
4
3
1
2
4
3
1
2
+U
Bat
4 … 20
m
A +
4 … 20
m
A –
GND
RS 485 A*
RS 485 B*
SDI-12 DA
TA
SDI-12 GND
A B
Screw ter
m
i
n
al strip
* SDI-12 protocol via physical
RS-485 i
n
ter
f
ace (
f
or co
nn
ecti
n
g to
OTT LogoSe
n
s a
n
d OTT DuoSe
n
s)
Fig. 8: Assignments for the screw terminal
strips A and B of the OTT CBS.
12