Cable Wiring; Using Without Aqua4Plus - Seametrics CT2X Instructions For Use Manual

INSTALLATION

Cable Wiring

If you buy your cabled sensor with a connector installed
(the normal configuration), no further wiring is needed.
For reference purposes, the first three diagrams below
show the pinout from the connector for various scenarios.
The final diagram shows the pinout if you bought your
sensor without a connector for use with SDI-12.
White
Purple
Yellow
Brown
Blue
Shield
For Modbus with firmware lower than 2.0
®
— with 5-pin connector
White
Purple
Yellow
Brown
Blue
Shield
For Modbus with firmware 2.0 or higher
®
— with 5-pin connector
White
Purple
Yellow
Brown
Blue
Shield
For SDI-12 with firmware 2.0 or higher
— with 5-pin connector
White
Purple
Yellow
Brown
Blue
Shield
For SDI-12 with firmware 2.0 or higher
— without connector
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1 12 VDC+ (Vaux)
2 Modbus D-
3 Modbus D+
4 Digital I/O (Not used)
5 12 VDC- (GND)
5-Pin
Connector
1 12 VDC+ (Vaux)
2 Modbus D-
3 Modbus D+
4 SDI-12 (Not used)
5 12 VDC- (GND)
5-Pin
Connector
1 12 VDC+ (Vaux)
2 Modbus D- (Not used)
3 Modbus D+ (Not used)
4 SDI-12 Signal
5 12 VDC- (GND)
5-Pin
Connector
12 VDC+ (Vaux)
Modbus D- (Not used)
Modbus D+ (Not used)
SDI-12 Signal
12 VDC- (GND)
Earth ground
Selecting Linear or Non-Linear Mode
All conductivity measurements are sensitive to temperature
change. The CT2X has built-in temperature compensation
to correct for changes in temperature. As a user, you can
select either a linear temperature compensation method or
a non-linear (nLFn) compensation method.
In the linear mode, a constant temperature coefficient is
applied to the readings. This defaults to 2.1% per degree
C, which works well for a wide range of applications. If you
want to use the linear method with a different coefficient,
then enter that coefficient in the Temp Coef box on the
Settings and Calibration window.
Natural waters, such as ground water, streams, and rivers,
often have a very low conductivity and do not respond to
temperature in a linear fashion. For this situation, the CT2X
provides a non-linear mode, which uses a complex formula
to calculate and apply temperature compensation to the
readings. This method meets the DIN EN 27888 standards.
If you want to use the non-linear method, checkmark the
Non-Linear box on the Settings and Calibration window.
The temperature coefficient box will disappear.
Using the CT2X Without Aqua4Plus 2.0
Most users will use the CT2X with Seametrics' Aqua4Plus 2.0
2.0. However, the CT2X is quite versatile, communicating
via either Modbus
®
do the following:
• Read a CT2X via Modbus
• Read a CT2X via SDI-12 protocol.
• Display readings from a CT2X on a panel meter.
If you want to use one of these methods, see the chapter
Direct Read Modbus
Page 9
CT2X INSTRUCTIONS
or SDI-12 interfaces, allowing you to
using your own software.
®
/SDI-12.
®
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