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LeveLine
®
Instruction Manual
10401-01026 Rev D
6.3. SDI-12 Digital Interface Wiring
In this configuration, the LeveLine
®
is usually in power saving (sleep) mode, during which
time the LeveLine
®
Logger will draw around 1mA from the external supply. The LeveLine
®
Mini versions will draw around 2mA when in sleep mode.
Requests for data on the SDI-12 bus will wake the LeveLine
®
up and there will be a delay of
up to 1 second before data is ready. The current drawn from the external supply by the
standard LeveLine
®
Logger/Mini when awake is less than 10mA. The -CTD versions draw
less than 20mA when awake.
As soon as data is ready to be sent, the LeveLine
®
will issue a ‘service request’ to the
controller. Once the controller has read the data, the LeveLine
®
will automatically re-enter
sleep mode.
Six Core Cable Usage
Core Colour
Designation
Connection
Red
Power ve
5V – 24V DC +ve power supply input
Black
Power supply –ve
Power supply ground
Blue
SDI-12
Controller SDI-12 I/O line
Green
RS485 +
Must be isolated and left floating
Yellow
SDI-12 / Modbus Select
Power supply -ve (see note below)
White
N/A
Not used. Cut back
Screen
Screen / Shield
Power supply or chassis ground
Note:
The yellow core is used to select between SDI-12 or Modbus (RS485) serial data
communications.
The yellow core must tied to the -ve power supply for SDI-12 mode.
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®
Ltd.
www.aquaread.com
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