Appendix D. RS-232 and RS-485 Operation
D-3
sensors that require lead lengths that exceed the limits of either RS-232 or
SDI-12 communications.
The SR50AT can be connected directly the RS-485 port on the CR6
datalogger.
D.2.1 RS-485 Wiring Using a MD485
show the wiring for the SR50AT in RS-485
mode.
TABLE D-3. Connections for RS-485 Mode
Colo
u
r Function
Connection
Black Power Ground System Ground and/or RS-232 Receiver Ground
(Pin 5 of a computer (DTE) DB-9 connector)
Red
Power
Power Source
+12V
Green
RS-485 A
MD485 RS-485
A
Terminal
White
RS-485 B
MD485 RS-485
B
Terminal
Clear
Shield
Shield/Earth Ground
FIGURE D-2. SR50AT to MD485 Wiring