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Appendix D. RS-232 and RS-485 Operation
D-4
D.3 RS-485 Wiring to a CR6 Datalogger
The SR50AT is a half-duplex device and can only be used on the
COM1
(
C1
and
C2
) terminal blocks.
TABLE D-4. Connections for CR6 RS-485 Mode
Colo
u
r
Function
Connection
Black
Power Ground
G
Red
Power
12V
Green
RS-485 A
C1
White
RS-485 B
C2
Clear
Shield
G
D.4 RS-232 and RS-485 Settings
Once the jumpers are set for RS-232 operation, a terminal program such as
Device Configuration Utility
or
Tera Term
can be used to change factory
defaults or existing settings. Use a terminal program that allows local echo.
The SR50AT does not echo key presses. To see what is being typed,
Local
Echo
must be switched on. A quick introduction to
Tera Term
is located in
(p. E-1)
. The following settings apply to
Device Configuration Utility
or any program used for communications.
Baud Rate:
Current SR50AT Setting
Note
Data Bits:
8
Parity:
None
Stop Bits:
1
Flow Control:
None
Local Echo:
On
The factory default baud rate is 9600 bps. Once the baud rate is
changed, the new baud rate must be used for further
communications to the SR50AT. Ensure to keep track of the baud
rate setting on the SR50AT. If the baud rate setting is unknown,
try using the default value of 9600 bps. If that does not work, start
the baud rate at 1200 bps and go through all the baud rate settings
until the correct one is found.
Select the following when using
Device Configuration Utility
).
•
Device Type:
Unknown
•
Choose the correct COM port.
•
By default, the baud rate in the SR50AT and
Device Configuration
Utility
is set to 9,600. Only change the baud rate if you know it has
been changed in the SR50AT.
•
Click on the
Connect
button in the lower left hand corner.
NOTE