Delta-T GP2 Data Logger User Manual

GP2 Data Logger
and Controller
Research-grade logger controller - capable of
complex calculated measurements and advanced feed-back control
User Manual
version 3.2
Delta-T Devices Ltd
Contents
CONTENTS ............................................................................................................... 2
UNPACKING ............................................................................................................ 4
OVERVIEW .............................................................................................................. 5
ABOUT SDI-12 ......................................................................................................... 6
DELTALINK SDI-12 TRANSPARENT MODE ................................................................ 7
TUTORIALS .............................................................................................................. 7
LAYOUT ................................................................................................................... 8
INSTALL DELTALINK ............................................................................................... 10
CONNECT TO GP2 .................................................................................................. 10
SOURCES OF HELP ................................................................................................. 11
CREATE A SIMPLE PROGRAM IN 6 EASY STEPS ...................................................... 12
THE GP2 SIMULATOR ............................................................................................ 13
SAMPLE PROGRAMS ............................................................................................. 14
CHECK SENSOR OPERATION AND START LOGGING ............................................... 14
RETRIEVE, VIEW AND SAVE LOGGED DATA ........................................................... 14
TO VIEW DATA IN EXCEL ....................................................................................... 14
SDI-12 CONNECTION ............................................................................................. 15
WIRING AND CONNECTOR REQUIREMENTS .......................................................... 17
GIVE EACH SENSOR A UNIQUE ADDRESS ............................................................... 20
SDI-12 SENSOR TYPES FOR USE IN DELTALINK ....................................................... 23
CREATE A GENERIC SDI-12 MEASUREMENT IN DELTALINK .................................... 26
TECHNICAL REFERENCE ......................................................................................... 29
SDI-12 INPUT PROPERTIES..................................................................................... 32
SDI-12 COMMANDS .............................................................................................. 35
SCREW TERMINAL CABLING .................................................................................. 39
TROUBLESHOOTING .............................................................................................. 41
APPENDIX 1: GP2 RELAY EXPANSION MODULE ..................................................... 42
Page 2
Contents
APPENDIX 2: GP2 NETWORK CABLING .................................................................. 46
APPENDIX 3: CABLE EXPANSION LID...................................................................... 50
APPENDIX 4: WS-CAN CANOPY ............................................................................. 51
APPENDIX 5: DL-MKT UNIVERSAL DATA LOGGER MOUNTING KIT ......................... 52
APPENDIX 6: M-ENCL-B2 ENCLOSURE WITH MODEM GATEWAY TO DELTALINK
CLOUD................................................................................................................... 53
APPENDIX 7: MAKE SURE THE GP2 IS PROPERLY SEALED....................................... 54
APPENDIX 8: UPGRADE GP2 FIRMWARE ............................................................... 55
GP2 SPECIFICATIONS ............................................................................................. 56
PRODUCT CARE AND MAINTENANCE .................................................................... 64
GP2 CALIBRATION CERTIFICATE ............................................................................ 64
LEGAL AND REGULATORY ADVICE ......................................................................... 64
WARRANTY AND SERVICE ..................................................................................... 65
INDEX .................................................................................................................... 67
Unpacking
Page 3
Unpacking
The GP2 package contains:
 GP2 Logger (with 6AA batteries to be fitted by the user)
 GP2-USB USB cable for GP2
 This GP2 User Manual
 Screwdriver and cable gland spanner
Accessory Options
GP2-RLY Relay Expansion Module - 4 extra relays and
power terminals
WS-CAN an open Protective Canopy with U-bolts and
logger mounting kit for GP2 or DL2e loggers
M-ENCL lockable enclosure
DL-MKT Universal Mounting Kit – a flat plate with U-bolts,
nuts and bolts for GP2, GP1 and DL6 loggers
GP2-G5-LID Expansion Lid with 5 cable glands for
3 to 10 mm dia. cables
5-way M12 connector (f) 5m cable to 100mm long flying
leads with bare wires SMSC/sw-05 for connecting SDI-12
network of EXT/5W-xx cables to GP2 logger
5-way M12 serial communication + power extension cables
(EXT/5W-xx where xx = 1, 5,10 or 25m)
GP2-NTP 5-pin network T- Piece with continuous screen,
for connection of loggers and EXT/5W-xx cables. Can be
used for logger comms and power networks (joining
multiple loggers together) or SDI-12 network
GP2-STP1 4-pin network T-Piece for networking of SDI12
sensors and EXT/5W-xx cables. Not to be used for
logger communication networks. Only for sensor SDI12 networks.
GP2-NPC Network Power Cable – to supply power via a
GP2-NTP and/or EXT/5W-xx cable
GP2-USB USB cable, 1.5m
GP2-RS232 RS232 cable, 1.5m
GP2/GP1-M8 network adapter cable, 1m
GP2-PSU Mains Power Supply1 with mains cable PC-XX
where XX = UK, EU, US, IN or CN
1
Not weatherproof, for indoor use only
Page 4
Unpacking
CON/5W-M-S-LD In-line M12 male 5-way connector to
screw terminals, with screened metal shell, for connecting
SDI-12 sensors fitted with screened cable to GP2 logger.
Accepts cable 4-9 mm diameter.
CON/5W-M-NS-SD In-line M12 male 5-way connector to
screw terminals, with unscreened plastic shell, for
connecting SDI-12 sensors fitted with unscreened cable to
GP2 logger.
Accepts cable 3-6.5 mm diameter.
CON/5W-M-NS-LD In-line M12 male 5-way connector to
screw terminals, with unscreened plastic shell, for
connecting SDI-12 sensors fitted with unscreened cable to
GP2 logger.
Accepts cable 4-8 mm diameter.
GP2-SER Service Pack:– battery holder, desiccant, cable
gland bungs & seals, lid screws, wire links, screwdriver,
and dust cap on lanyard
Plugs with screw connectors are available for adding to the M12 connector system.
Overview
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2
The GP2 has 12 differential analogue input channels2, four event/digital
counter channels, and a serial input channel for up to 62 SDI-12 sensors or a
single WET sensor.
Two output relays can be extended to 6 using a relay expansion module.
Two banks of terminals provide a 3V precision reference, or unregulated
power for sensors. There is also one 5V and one 12 V power terminal.
Each sensor can be read at a different rate, from 1 second to >1000 days.
Multiple recording rates are possible for any combination of measurements.
Multiple recording types are provided:- average, minimum, maximum, total,
integral, wind-rose, conditional.
The logger can hold about 2.5 million readings.
Each relay can control a separate experiment, zone or test protocol, each
based on different threshold settings or conditional logic.
Simple programs are quickly created on your PC, assisted by the sensor
library and a helpful user interface, and then sent to the logger.
Sophisticated program scripts can be created without having to learn a
programming language or typing out any commands.
New measurements can be created mathematically along with complex
control algorithms, using algebraic and trigonometric functions and conditional
logic, with easily created sequences of instructions.
or 24 single-ended analogue channels – but note the limitation on the number of cable glands.
Overview
Page 5
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You can create and manipulate your own “variables” for e.g. disease risk
factor, integral error, days since soil moisture below a threshold, etc.
Thresholds can be changed while logging, by using program settings.
A simulator assists the checking and understanding of the behaviour of
logging and control programs. A weather pattern can be repeated, or new one
randomly created. It is particularly useful for irrigation.
Video tutorials, online help, a sensor library and friendly user interface are
provided for the DeltaLINK 3 software.
Sensors Supported
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All Delta-T sensors. Many third-party sensors, including SDI-12.
User defined sensors based on voltage, current, resistance, bridge,
potentiometer, counter, frequency and digital state sensors.
Any number of calculated measurements.
About SDI-12
SDI-12 is a communication protocol which enables sensors with a built-in
microprocessor to share a single 3-wire cable to send data to a data logger.
SDI-12 stands for serial digital interface at 1200 baud.
It is widely used by the water industry, typically for monitoring water catchment
areas and for measuring soil moisture and other environmental data.
Features and Benefits of SDI-12
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Reduced system costs.
Simplified and lower cost cabling requirements (can be 3-core)
Use of a single data logger for multiple sensors on one cable
Power is supplied through the same cable.
Sensors can be interchanged without re-programming the logger with
calibrations and other parameters.
Use of a 'standard' interface eliminates complexity in logger design.
Level of interoperability between different manufactures' devices.
Battery powered operation, with minimal current drain.
The SDI-12 standard enables a sensor to store and provide some metainformation about itself (e.g. manufacturer, product name, serial number).
This can be of benefit in permitting the interchangeability of sensors and
obtaining higher accuracy.
GP2 SDI-12 Features and Benefits
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Page 6
SDI-12 measurements are available for recording and processing in
DeltaLINK 3.2, alongside ‘conventional’ analogue and digital measurements.
They can be:
- added to recordings
- used in Scripts, Conditions, and Calculations
- viewed via Read Now, to check sensor operation.
About SDI-12
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Many third-party SDI-12 sensors are predefined in a sensor library add-in for
DeltaLINK. They are easily added to a program, but first each needs a unique
address. (The GP2 SDI-12 Transparent Mode is suitable for doing this)
SDI-12 cuts down the amount of sensor cable you need – one daisy chain
instead of a star network.
Delta-T’s cabling with 5-way M8 connectors can be used.
The same cable can supply 12V power to all the sensors.
Up to 62 SDI-12 sensors can be connected to a GP2 logger in addition to its
standard analogue and digital sensors (limited by the number of SDI-12
addresses available, cable length, program measurements and GP2
memory).
Up to 300 different measurements can be recorded at a time (limited by the
GP2’s capability) .
For example, you can connect up to 50 PR2/6 6 channel sensors.
The serial communications format avoids many of the problems typically
associated with long cable runs from sensors with analogue output signals.
The SDI-12 protocol allows for the use of self-calibration algorithms within the
sensor itself.
Existing GP2s are in-field upgradeable (no need to return to Delta-T):
The existing Delta-T M12 x 5-way cable system can be used.
See page 15.
Re-wireable connectors (i.e. with internal screw-terminal connectors) are
available to interface 3rd party sensors to the Delta-T cable system.
Re-wireable connectors are also available to interface the PR2 SDI-12 sensor
with third party loggers.
See page 39.
DeltaLINK SDI-12 Transparent Mode
Type in commands to a sensor via a command box and see it reply in an output
box. This way you can do the following:
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Discover and change a sensor address.
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Change a sensor configuration.
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View optional diagnostic detail.
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Power up the SDI-12 bus.
When you issue a command, the logger turns on the SDI-12 power supply
before sending the command.
If a sensor takes longer to power up the logger re-issues the command.
See DeltaLINK’s context sensitive online Help.
Tutorials
See GP2 Intro Series Tutorials at
http://www.youtube.com/user/DeltaTDevices/videos
DeltaLINK SDI-12 Transparent Mode
Page 7
Layout
Page 8
Layout
Event Channels
Use Event 1 or 2 to monitor fast switch closures or pulses up to 30 kHz, such as a
flow meter.
Use Event 3 or 4 to monitor slower switch closure or pulses <100Hz, such as a rain
gauge. A 5ms de-bounce feature reduces the risk of double counting.
Relay Channels
The Relay channels have an open or closed latching switch, protected with a resetting
thermal-fuse. They can be used in a variety of ways, e.g. to control several different
experiments or irrigation zones, or alarms, or to switch power to sensors.
Each relay can switch up to 1A at 24VAC or 32V DC.
See also the Relay Expansion Module on page 42.
Status LED
Two flashes per ten seconds means the GP2 is logging.
Four flashes in a group indicate an error.
No flash means not logging or no battery power.
If the logger locks up, briefly press the Reset button.
After pressing Reset, 4 LED flashes indicate that the GP2 is doing a warm reset.
Your program and data are preserved and logging will resume.
Hold Reset for more than 5 seconds until a second set of four LED flashes occur to
initiate a cold reset. This restores the factory-set default program and deletes all data
including any program which you may have added.
After releasing the button, there is a short delay (a few seconds) before the logger
starts erasing the flash. The LED flashes continuously whilst the logger is busy doing
this. Wait for this flashing to end, and don’t press any button or try to communicate
with the logger - it could take up to a minute. This confirms the cold boot was
successful and is complete.
Analogue Channel Considerations
The differential analogue channels accept signals nominally
0 to 2.5V, with a full signal range of -1.4 to +2.7V.
The input range of custom sensor types can be set to autorange or to fixed ranges.
Ensure each voltage input on the (+) or (-) terminals is kept
within the permitted common mode range of -2.5V to +3V relative to
logger GND. Ensure these limits are not exceeded, particularly if
powered sensors are not powered by the GP2. The input signal may
need to be connected to the logger ground. If the signal is floating
then place a 10kohm resistor between (-) and (SGND).
Sensor Power
Analogue channels have (PWR) terminals to allow power to be
switched to sensors. Sensors can be powered with an adjustable
warm-up time prior to taking a reading. The duration of the warm-up
period can be increased in multiples of one second.
Layout
Page 9
The PWR power terminals associated with channels 1 to 12 can supply a regulated
or unregulated voltage.
On Bank A and B the GP2 can provide either 3V (±0.2mV) or 5 to 10.5V
(unregulated). In addition, 5V (±2%) and 12V (±0.4V) DC are available on separate
screw terminals. External power can also be switched to sensors via the two
internal relays and four extra relays of the Relay Expansion Module.
The WET sensor PWR terminal also supplies 5.0 to 10.5 VDC unregulated and can
be used by another sensor if no WET sensor is connected.
Install DeltaLINK
To operate the DeltaLINK 3 software for the GP2 logger you need:
 A PC running Windows 10 or later.
 One free USB or RS232 port.
 Internet connection for software install.
 GP2 to PC USB cable (supplied with GP2).
1. Obtain DeltaLINK 3 from http://www.delta-t.co.uk.
Read the Release Notes in the Document Library or at http://www.delta-t.co.uk.
2. Select Install DeltaLINK and follow the on-screen instructions.
3. Setup creates a desktop shortcut to DeltaLINK and puts a Firmware Upgrade
program, a GP2 Calibration Certificate Generation program, and a Document
Library folder in the DeltaLINK 3 program group.
4. Install USB drivers for the cable. See https://ftdichip.com/drivers/vcp-drivers/ and
FAQ “How do I set up my USB to RS232 Converter?” at https://deltat.co.uk/frequently-asked-questions/set-usb-rs232-convertor/.
Connect to GP2
1. Connect GP2 to the PC using the USB cable
provided (ensure drivers are installed, see
above).
2. Run DeltaLINK.
3. If DeltaLINK discovers your logger, it displays
this in the status bar – see at right.
4. If the GP2 is not found select Connection
Details, Add,
Details, Detect USB
Port or select the
correct COM port
from the drop down
list.
See How to find your
USB COM port on
page 49 .
If using networked loggers see page 48.
Page 10
Install DeltaLINK
Sources of Help
Online Help
Click Help from any DeltaLINK window (or press F1) in selected areas for context
sensitive information about DeltaLINK operation and functionality.
Select Start, All Programs, Delta-T Devices, DeltaLINK, Document Library.
Video Tutorials
Before attempting to program the GP2 watch the video tutorials –
at http://www.youtube.com/user/DeltaTDevices/videos.
These tutorials show the progressive development of a soil moisture sensor
program, followed by its use to control soil moisture using an irrigation control relay.
Run DeltaLINK at the same time and see if you can reproduce the instructions
along with the instructor.
Sensor Wiring Instructions
Wiring, installation and programming notes are provided for all sensors in the GP2
sensor library. This information appears in the Info Panel when a sensor is selected in
the Measurement section as shown in Step 2 below,
Left click on the wiring diagram to enlarge it.
If wiring up in the field, it may help to have these printed - see steps 3 & 4.
Sources of Help
Page 11
Create a Simple Program in 6 Easy Steps
Before you start you need to have DeltaLINK connected to your GP2 (see above),
or to the GP2 Simulator (see below).
1.
2.
3.
4.
5.
6.
Page 12
Select Program
Select Change
Click on “Click to add new item, under Measurement.
Select Temperature (or any other option from the list)
Select 2K Thermistor (or any other option)
Select Apply to send the program to your GP2 or the simulator
Create a Simple Program in 6 Easy Steps
You can now, if you wish, click on the Sensors tab and Read Now to watch realtime readings, or select the Logger tab and Start Logging.
Note after step 5 above, the icon and label for the sensor appear in the
Measurement list in the left hand window. Also, detailed properties for the chosen
sensor appear in the right hand window, including the channel number, and, as we
saw earlier, the sensor connection instructions appear in the lower left Info Panel.
Under Recording the row labelled Individual reading indicates a rate of once per
hour. To change this, select the row – which will open the recording options on the
right hand panel, and choose your own Recording rate.
Note: Before you can change a program, stop logging and delete the logged data
(select Logger, Stop then Delete Records).
The GP2 Simulator
This simulates the weather and its effect on a
variety of sensors. Before sending a program
to your logger, try it out on the Simulator.
You can speed up time in the simulator to
check the behaviour of your program.
Restart the simulator and it will recreate the
same weather as before, from the same date.
This lets you see the effect of changes to a
program.
(Note the simulated weather uses an artificial
pattern and pseudo-random numbers, so don’t
rely on it for anything important.)
Connect to GP2 Simulator
1)
Graphs of solar radiation, rain, soil
moisture, salinity and temperature
generated by the DeltaLINK
Simulator
Ensure DeltaLINK is connected to the GP2
Simulator as follows:a) Select Connection Details, Add and on the Connection Properties,
Connection tab set Connect to logger using to Simulator
b) On the Details tab set Select simulator model to GP2 simulator.
2) Click on OK, then OK again to connect
The GP2 Simulator
Page 13
Sample Programs
Several are provided. To use these go to the Program tab, click on the Change, select
Edit, Import Sample Program, and select one from the Open dialog.
Check Sensor Operation and Start Logging
1. Select the Sensors window and click the Read now button. The sensor readings
will continually refresh on a scrolling time graph.
2. Observe the sensor reading display in the scrolling charts and value panels while
adjusting sensor wiring and/or installation conditions.
3. Click the Cancel button when finished.
4. Once sensors are setup select the Logger tab and click Start to commence
logging.
Retrieve, View and Save Logged Data
1. Select the Dataset window. All stored
data in the logger will be retrieved and
displayed on the screen.
Click Refresh if required.
2. Select File, Save to save the data to a
dataset file on your PC.
To view data in Excel
This helps import logged data files into MS
Excel spreadsheets.
1. Open a previously saved (see above) dataset file (*.dt6 file extension).
2. Select File, Save As to change the file to a *.csv format for opening in Excel:
Page 14
Sample Programs
SDI-12 Connection
Ensure you are running the latest version of DeltaLINK and have firmware 2.1 or later. If you
need to upgrade the firmware, please refer to the instructions in Appendix 8.
Cabling Connection Options
GP2-STP1
Figure 1: Wiring system used to connect SDI-12 sensors to the GP2 Logger
controller, using cables with integral 5-way M12 connectors.
You can use this system to reliably connect 10 SDI-12 sensors on a total cable
length of 600m (2000 feet). In many cases more sensors and/or longer cable
lengths are possible.
M12 Connector tightening
**Warning**
When connecting multiple cables and T-piece together, it is essential that any
M12 connector is tightened sufficiently:

Ensure internal connector O-ring and opposite sealing face are free from
dirt.
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Tighten the connector thumbscrews as much as you can by hand or use
a torque driver set to 1Nm to be sure. See video:
SDI-12 Connection
Page 15
https://youtu.be/BLo1k5fYqao
We recommend the Weidmuller “1900021000” torque driver:
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Page 16
This will save lots of painstaking trouble shooting hours if you do have a
loose connection and give you piece of mind that all connectors are
correctly tightened.
Untightened connectors can come undone and let water into the cable
network which can damage cores and cause erroneous readings.
SDI-12 Connection
Wiring and Connector Requirements
SDI-12 uses a 3 wire cable with sensors attached along it – as in a daisy chain.
The wires are used for Power (12V DC), Ground (0V) and Serial Data (5V).
The SDI-12 specification states…
“The SDI-12bus is capable of having at least 10 sensors connected to it, each with
200 feet of cable. With fewer sensors, longer cable lengths are possible.”
But note also…
“…the voltage drop between the data recorder and all sensors [should be] less
than 0.5 volts during the maximum combined sensor current drain.”
For further technical detail on requirements see SDI-12 standard (v1.3) at
www.sdi-12.org
Worked Example of an SDI-12 Cable Length Calculation
The SDI-12 cable provided by Delta-T has a resistance of 0.06 ohms per metre,
so to meet the 0.5V voltage drop restriction the maximum length of cable, in
metres, between each sensor and the GP2 is
1000 * 0.5 / (0.06 * Ima) = 8333 / Ima
…where, for Sequential measurements (see page 32), Ima is the sensor supply
current in mA when it is active.
For Concurrent measurements Ima is the combined active supply current of all
sensors in a Concurrent group (see page 32) and the formula provides a worst
case estimate of maximum length of cable between the GP2 and the most distant
sensor in the Concurrent group.
For further technical detail on requirements see SDI-12 standard (v1.3) at
www.sdi-12.org
Wire SDI-12 network cable to GP2 logger controller
Wire colour
SMSC/sw-05
Black
Blue
Green
White
GP2
terminal
Function
M12 Connector
Pins
SDI-12 DATA
SDI-12 Data
Sensor ground power return
Screen
Sensor power
4
3
Screen
2
GND
12V
SDI-12 Power supply requirements
GP2 provides switched +12V @ 500mA either from its internal batteries or from an
external source.
Wiring and Connector Requirements
Page 17
To avoid rapidly depleting the GP2 battery an external GP2 power supply is
recommended if sensors need several 10’s of mA or are intended to operate
below 10 °C.
Alternative methods of powering sensors are:
Use of GP2 relays to switch in external power.

Permanent power supply to sensors which don’t tolerate power cycling.
SDI-12 to GP2 logger wiring connections- using logger
power
Figure 2: Sensor connection to the SDI-12 channel in the GP2 logger, using the
logger’s internal 12V Power channel.
Colours shown are for cable type SMSC/sw-05.
SDI-12 to GP2 logger wiring connections- using
external power
Figure 3: Sensor connection to the SDI-12 channel in GP2 logger, using an
external permanent (i.e. un-switched) power supply or battery connection.
Colours shown are for cable type SMSC/sw-05.
Page 18
Wiring and Connector Requirements
M12 connector sensor wiring connections for SDI-12
3
GROUND
SDI-12 DATA
SDI-12 POWER
SCREEN (if present)
4
4
2
5
3
GROUND
SDI-12 DATA
SDI-12 POWER
1
4a. Pin connections for connector
type CON/5W-M-S-LD,
for sensors with screened cable*
4
4
2
5
1
4b. Pin connections for connector
types CON/5W-M-NS-(LD or SD)
for sensors with unscreened cable
Figure 4: Pin connection diagrams for field attachable 5-way M12 connectors used as
part of the Delta-T M12 SDI-12 cabling system to connect to the SDI-12 channels of
the GP2 logger as shown in in Figures 2 or 3
*Note: When using screened cable take care to clamp the screen securely to the
metal shell of the connector.
See also Screw terminal cabling on page 39.
Wiring and Connector Requirements
Page 19
Give each Sensor a Unique Address
Know this
Give each SDI-12 sensor a unique address before connecting it into a network of
other SDI-12 sensors.
Delta-T DeltaLINK Logger software provides a mean for doing this, called the
SDI-12 Transparent Mode.
Note: If two sensors have the same address the SDI-12 network will not work.
A new sensor will typically have the address set to 0 (number zero).
Give each sensor a unique address.
This can be one of the following 60 addresses:0 to 9, a to z, or A to Z.
(Other printable characters such a punctuation marks are permitted but think
carefully before using such characters).
Open DeltaLINK Transparent mode
You need a GP2 connected to a PC running DeltaLINK v3.2 or later.
With no other sensors on the network connect the sensor to the GP2 SDI-12
channel.
In DeltaLINK select Tools, SDI-12, Transparent mode to open the SDI-12
Transparent mode terminal as shown below.
Once the SDI-12 Transparent mode terminal is open, as shown above, the GP2
behaves as a transparent serial link between sensors on the SDI-12 network and
the PC.
Page 20
Give each Sensor a Unique Address
About the SDI-12 Transparent Mode
The SDI-12 Transparent mode terminal can be used to make changes to sensor
configurations and discover and change their address.
Use this terminal window by typing in the command box at the top, and the
response from the sensor will be displayed in the output box below.
When you issue a command the logger with turn the 12V power supply on before
sending the command.
Some sensors takes longer to powerup, and so you will see the logger
resend the command. It will also add
Command box
the command terminator “!” if you
forget it.
Messages box
Here the output box shows the logger
tried 7 times before the sensor has replied - with address “0”.
Ensure only one sensor is connected on the SDI-12 network.
Example: Use Transparent Mode to set an address:
We assume the SDI-12 Transparent mode in DeltaLINK, Tools has been selected,
as shown above, and is running, so your PC keyboard is communicating
transparently through the GP2 directly with the SDI-12 network.
We also assume you only have one sensor on the SDI-12 network, and it is your
new sensor, and we want to give it a unique new address.
1. Display sensor’s address using the Query “?!” command.
This identifies the address of a sensor.
The sensor must be alone on the bus … otherwise all sensors will ‘shout at once’
and send their own address.
In the Transparent mode command box type ?! followed by Enter.
In the output box you see3 the following
response from the sensor
?!a
Command
Response
Command terminator
We would normally expect this address to be zero for a new sensor, but it might
not be.
Here the address reported is “a” (It could be a-z, A-Z or 0-9)
You may already have another sensor with this address.
3
There is also a hidden <Carriage Return> <Line Feed> string at the end of each message,
which just acts to display the next reply on a new line.
Give each Sensor a Unique Address
Page 21
2. Confirm it works: tell sensor to identify itself.
The command I! displays a sensor’s identification: manufacturer’s name, model
and other details.
Note: SDI-12 commands are case sensitive.
Note: All SDI-12 commands start with an address (apart from ?) and finish with !
DeltaLINK is quite forgiving and will add the terminating ! if you forget.
You type
Response
aI!
a13Delta-T PR2SDI00200000000010001
The logger asks the sensor
at address “a” to identify
itself.
It replies with a long string of
characters which is different
for each manufacturer.
a13Delta-T PR2SDI0020000000010001<CR><LF>
Serial number
Version
Sensor model number
Manufacturer
SDI-12 standard version 1.3
Carriage return,
Sensor address
linefeed
3. Change its address
You type
Response
aAb!
b <CR><LF)
Your sensor now has the address “b”
Before putting a sensor on the SDI-12 network ensure it has a unique
address, or you will bring the network down.
Page 22
Give each Sensor a Unique Address
SDI-12 Sensor Types for use in DeltaLINK
A custom SDI12 Sensor Library resource file containing a range of other
manufacturer’s sensors is freely available for download from the Support/
Software Downloads pages at www.delta-t.co.uk.
We provide this free of charge and have confirmed that the sensors work with the
GP2 but we make no claims on the suitability of the sensors or the sensor type
code and do not generally provide technical support for them.
Generic SDI-12 sensor types (powered and unpowered) are provided in
DeltaLINK. These can be copied and adapted to suit your sensor. You will need to
read the supplier’s data sheets and may also need to read the SDI12 standard at
www.sdi-12.org.
Download Custom Sensor Library from
Support/Software Downloads pages at
www.delta-t.co.uk
Is it
in the Custom
SDI-12 Sensor
Library?
YES
Import sensor type
into DeltaLINK
Sensor Library
Editor
NO
Read sensor manufacuture’s data sheets
Create your own custom sensor type in
DeltaLINK’s Sensor Library Editor,
or
modify the properties of a Generic SDI-12
sensor type in the DeltaLINK Program Editor
Figure 5 Decision Tree on obtaining Sensor Types for DeltaLINK
for use with SDI-12 sensors from other manufacturers.
SDI-12 Sensor Types for use in DeltaLINK
Page 23
Import the Custom SDI-12 Sensor Library
1)
2)
Page 24
3)
4)
5)
Ensure the latest version of DeltaLINK is installed on your PC.
Connect a GP2 running firmware version 2.10 or later,
or select Edit, New Program, GP2 Multifunction Program.
Select Program tab and wait for the current program to appear.
Select Edit, Sensor Library Editor.
Select Edit.
6)
Under Custom Sensor Types, Right click to display a list of options
7)
8)
Select Import Custom Sensor Library.
Browse to the downloaded copy of the sensor library file and click on
Open.
SDI-12 Sensor Types for use in DeltaLINK
9)
Choose and select which sensors you wish to import and click on Import
selected sensor types.
10) Click to close message announcing the process succeeded and examine
the sensors now listed under Custom Sensor Types in the Sensor Library
Editor.
Custom SDI 12 Sensor Types
Figure 6 SDI 12 Sensor types as displayed in DeltaLINK after importing the
entire SDI 12 library.
Note: This list is liable to change without notice. One example of each third party
sensor is tested to see if it worked with a GP2 but Delta-T do not distribute and
do not support them.
The one exception to this rule is the BS5 pressure sensor, which we do sell and
support.
SDI-12 Sensor Types for use in DeltaLINK
Page 25
Create a Generic SDI-12 measurement in
DeltaLINK
1.
2.
3.
4.
5.
Start GP2 Program Editor.
Click Change.
In Measurements list select Click to add a new item.
Select the Generic menu.
Select SDI-12, powered
or select SDI-12, not powered if providing an independent (i.e. not switched)
power supply.
Note: Each GP2 measurement holds a single value. Multiple GP2 measurements
are required to hold a collection of values from a multi-parameter sensor.
Page 26
Create a Generic SDI-12 measurement in DeltaLINK
Set Measurement’s Input Properties
To continue you may now need to cross-refer to the references section on SDI12
Input Properties on page 32
In particular you must set the correct address for the sensor (see 6 below).
6
7
8
Here an SDI-12 measurement has been added.
On the right, in the Properties panel, you can see the sensor measurement
properties, including Input properties:
Some settings are common to all measurements such as Measurement name,
Calculation, Result, Power channel, Warmup duration, Sensor type, Input type,
and Channel are given default options by DeltaLINK.4
6. Earlier, using the DeltaLINK SDI-12 Transparent mode you should have
ensured the SDI-12 sensor has a unique address, see page 20.
Now set the measurement input Address field to the same address.
7. Refer to the sensor manufacturer’s data sheets for information on the
other SDI-12 properties that need to be set.
See also:
SDI-12 Input Properties on page 32
SDI-12 Standard (v1.3) at www.sdi-12.org
8. Specify the Power channel.
The GP2 +12V supply is designed for SDI-12 sensors.
All other options are available, including the use of relays to switch an
external supply.
4
Requires DeltaLINK 3.2 or later.
Create a Generic SDI-12 measurement in DeltaLINK
Page 27
9
9.
Specify the Warmup duration. This defines the time between the turn on of
power and the sensor being able to receive commands. Do not confuse it with
the Measurement duration. Sometimes this is not specified in data sheets.
Use 1s unless a sensor requires longer than this.
Set Calculation and Results Properties
Expand the Calculation and Results properties by
clicking on the down arrow as displayed the right.
The default measurement calculation offered by
the generic DeltaLINK SDI12 Measurement is
displayed. It says “No calculation” which means
that DeltaLINK will simply pass on the
measurement it receives from the SDI12 sensor.
From here on the SDI12 sensor output can be
treated like any other sensor connected. So at this
stage if you wish you can use the full power of the GP2 to do complex maths on
this measurement.
Result properties
As with all DeltaLINK sensor measurements ensure the permitted range resolution
needed for your readings are appropriate.
For further help highlight a parameter and then press F1.
Logging interval
The minimum logging interval may vary depending on how many sensors you
have connected to the SDI-12 network. DeltaLINK gives you an option of logging
every 1s, which may be fine for analogue readings but not with SDI-12.
SDI-12 sensors can have a measurement duration which may last longer than 1s.
In addition to this it is prudent to allow at least another half a second per SDI-12
measurement.
If a reading cannot complete in the time available, then the previous SDI-12
reading for that sensor will be reported. So one way of discovering how fast you
can take reading is to vary the relevant environmental parameter increasingly
quickly and find out at what recording rate the readings fail to keep up with the
rate of change.
Page 28
Create a Generic SDI-12 measurement in DeltaLINK
Technical Reference
GP2 Program and Sensor Library Editor
In the GP2 Multifunction Program Editor, the Measurements list pop-up menu
offers Generic SDI-12 Sensor types (‘powered’ and ‘not powered’ variants).
SDI-12 Sensor types, from other suppliers are available for importing into the
sensor library. These are free to download from the Support/Software Download
pages at www.delta-t.co.uk.
To import these into the Sensor Library Editor click Edit, right-click in Custom
Sensor Types and select Import Custom Sensor Library.
These all have ‘SDI-12’ as their Input type, a collection of SDI12-specific
properties (such as SDI-12 Address) which can be assigned in the same way as
properties of other Input types, together with the same General, Calculation and
Result properties as other measurements.
Measurements based on these SDI-12 Sensor types can then be selected in
Recordings, and entered into Custom formulae, Conditions and Scripts in the
same way as other measurements.
In the Sensor Library editor, the ‘SDI-12’ Input type can be selected to create
custom SDI-12 sensor types.
SDI12-specific properties allow default or ‘Additional’ SDI-12 measurements to be
selected, in Sequential or Concurrent mode (i.e. aM, aMn or aC, aCn commands),
with or without CRC5. Each GP2 measurement holds a single value, so the
position in the list of values returned by the sensor has to be specified. Multiple
GP2 measurements are required to hold a collection of values from a multiparameter sensor.
The GP2’s +12V output is intended for powering the SDI-12 bus and can source
500 mA. Other GP2 outputs can be selected as the Power channel, or <none> if
using an independent power supply. Concurrent measurements can be assigned
to ‘Concurrent groups’, which are measured separately, to avoid overloading the
SDI-12 power supply.
SDI-12 firmware operation
GP2 Programs perform program actions (Recordings, Scripts, etc.) on 1s clock
ticks. This means that all measurements which the program needs to process
need to be complete within 1s of the time when they are due. Thus for analogue
measurements, the GP2 schedules warmups to occur in advance so that sensors
are powered up, settled and ready to be measured when required.
Similarly, the GP2 accommodates SDI-12 measurements, which can take several
seconds (or even minutes) to complete, by performing them in advance. This
ensures that measurement values are ready for processing when required, but
there is inevitably a delay between the measurement itself and the time when it is
used by the program. The SDI-12 ‘bus latency’ is the maximum delay incurred by
any SDI-12 measurement: it is the time required to complete all the SDI-12
measurements in the program, plus a contingency for retrying – as explained
below.
5
Cyclic Redundancy Test is a method of checking the reliability of serial data
Technical Reference
Page 29
In general, the delay between any SDI-12 measurement and the time when its
value is used in the program may be as long as the bus latency – but no longer. If
a program requires SDI-12 measurements more frequently than the bus latency, it
may use duplicate values – but these will be no older than the bus latency.
Similar behaviour occurs in DeltaLINK’s ‘Read Now’, where duplicate values are
shown until an updated value becomes available.
The SDI-12 specification stipulates that a SDI-12 recorder is required to retry
several times if a command does not receive an error-free response. The GP2
provides a contingency for retrying, so sequences of SDI-12 measurements
normally complete several seconds before the programmed time. It is not
practical to allow for the worst case – where all SDI-12 commands fail in the most
time-consuming manner. The time allocated by the GP2 for retries guarantees a
99.99% success rate, if 10% of SDI-12 commands randomly fail.
Transparent mode terminal
A Transparent mode terminal is a requirement of the SDI-12 specification, and is
normally required at least to configure the addresses of SDI-12 sensors.
The Tools > SDI-12 > Transparent mode command opens the ‘SDI-12
Transparent mode terminal’ window. Type a SDI-12 command in the command
box, click Send and observe the response in the output box.
If the GP2 is programmed for SDI-12 measurements and a Power channel is
selected, the GP2 activates the SDI-12 Power channel before transmitting the
command. Otherwise, the GP2 activates the default +12V output.
The command is transmitted immediately, so if a sensor is slow to start up, the
command may fail. The Power channel remains powered for 30s after completing
any command, so clicking Send a 2nd time normally succeeds.
The GP2 transmits the command, including <break> and retries, according to the
rules of the SDI-12 protocol. The output box displays all SDI-12 commands and
responses.
Enable ‘Show diagnostic detail’ to view timings and result codes for each
transmitted command.
SDI-12 Sensor requirements
Sensors should conform to the SDI-12 standard v1.3 at www.sdi-12.org.
Some third party sensors can be unstable unless powered continuously.
These can be accommodated by arranging the sensor cabling with two power
lines, one switched by the logger, the other permanently connected to a second
supply.
Each SDI-12 sensor must be assigned a unique address before putting it on the
SDI-12 network. This can be done using the DeltaLINK Transparent Mode.
Page 30
Technical Reference
Versions
SDI-12 support is introduced in GP2 firmware version 2.10, which is distributed as
the firmware upgrade in DeltaLINK 3.2.
Compatibility
GP2 programs created in DeltaLINK 3.2 require GP2 firmware 2.10 (or later), and
are not compatible with earlier firmware versions.
Datasets created by firmware 2.10 require DeltaLINK 3.2 (or later) and are not
compatible with earlier DeltaLINK versions.
DeltaLINK 3.2 installs ‘side by side’ with earlier DeltaLINK versions, so an earlier
version can be retained for working with earlier GP2 firmware versions.
All GP2s are built with SDI12-capable hardware and firmware 2.10 is fully
compatible with all existing GP2s.
Page 31
SDI-12 Input Properties
Channel groups (in Sensor Library editor)
Select the SDI-12 sensor channel group to SDI-12.
Address
Select the SDI-12 address of the sensor.
Each SDI-12 sensor must have a unique address. Type the aAn type command in
the DeltaLINK’s SDI-12 Transparent mode terminal to set a sensor’s SDI-12
address.
See also Give each Sensor a Unique Address on page 20
Mode
Select Sequential or Concurrent.
In Sequential mode, the sensor will be the only active SDI-12 sensor when making
its measurements; all other SDI-12 sensors will be in low-power quiescent mode.
In Concurrent mode, other SDI-12 sensors can be active and making
measurements at the same time.
Concurrent mode speeds up throughput of SDI-12 measurements because it
allows sensors to make measurements in parallel. However, this requires all
active sensors to be powered up at the same time and may impose a large load
on the SDI-12 power supply. To avoid overloading the SDI-12 power supply,
Concurrent measurements can be separated into Concurrent groups. To
minimize loading of the SDI-12 power supply select Sequential mode.
Sequential mode uses the SDI-12 'M' (start measurement) commands.
Concurrent mode uses the 'C' (start concurrent measurement) commands. Some
SDI-12 devices don't provide concurrent measurement commands - refer to the
manufacturer's documentation.
Concurrent group
This applies to: Measurements, if the Concurrent mode is selected.
Assign measurements to different groups if you need to avoid overloading the
SDI-12 power supply.
If required, enter the name of the group that you want to assign the measurement
to, for example ‘Group 1’, ‘Group 2’. All measurements in the same Concurrent
group are performed in parallel, but separately from measurements in different
Concurrent groups.
In any case, Concurrent measurements are performed separately from Sequential
measurements.
Additional
Select Yes to use a SDI-12 'additional' measurement or concurrent command and
select the Measurement number (below), or No to use the default measurement
or concurrent command.
Page 32
SDI-12 Input Properties
Refer to the manufacturer's documentation for details of the measurement that
you need.
One example of the use of the Additional property is its use when sensors can
present data in different units. For example a soil moisture sensor may be able to
output data in units of permittivity ἐ, or as volumetric water content in m3.m-3 or as
a percentage.
If this is the case with your sensor then it should say what to do in the sensor’s
user manual. If it does not say anything then leave this option as No.
If these or other additional options are available then select Yes, then chose the
relevant Measurement number as described in the next section.
Measurement number
Applies if: Additional is Yes
Select the SDI-12 additional measurement number.
This could be used, for example, to express the data in different units, as
described above under Additional.
CRC
Select Yes to request the sensor to provide a CRC (cyclic redundancy checksum)
with its measurement results. The logger checks the CRC to confirm it has
received the measurement results correctly.
Some SDI-12 devices don't provide a CRC - refer to the manufacturer's
documentation.
Value position
Multi-parameter SDI-12 sensors may provide more than one value for each
measurement. Refer to the manufacturer's documentation and select the position
of the result which you require in the list of values provided by the SDI-12
measurement.
If the SDI-12 measurement requires more than one SDI-12 'send data' command
to send a complete set of values, enter the cumulative position of the value which
you require. For example, a profiling moisture sensor may provide the values for
10, 20, 30 and 40 cm depths in the first 'send data' command and the 60 and 100
cm values in the 2nd 'send data' command. To obtain the 60cm value, select
Value position '5'.
Measurement duration (s)
Enter the number of seconds that the SDI-12 measurement takes.
If the information isn’t provided in the manufacturer’s documentation, enter the
measurement command (of type aM, aMn or aC, aCn) in the DeltaLINK SDI-12
Transparent mode terminal. The Measurement duration is in digits 2 to 4 of the
sensor’s response. For example, if the response is ‘10024’ the Measurement
duration is ‘002’, i.e. 2 seconds.
Send data command.
Select the SDI-12 'send data' command which provides the required result.
If the sensor provides the result in the first 'send data' command, the Send data
command is 'D0'.
SDI-12 Input Properties
Page 33
In the profiling sensor example above, the appropriate Send data command for
the 60 cm or 100 cm values would be 'D1'.
SDI-12 units
Enter the units of the result provided by the SDI-12 measurement.
You can perform additional calculations on the SDI-12 measurement result by
selecting Calculation properties.
Power channel
The GP2’s +12V channel is designed to provide up to 500 mA for powering the
SDI-12 bus.
If your SDI-12 sensors have a high current consumption it is advisable to power
the GP2 from an external power supply - otherwise, the +12V channel may be
unable to power the sensors as the internal battery ages and at low temperatures.
Peak current consumption can be reduced by selecting Sequential mode (above)
for power-hungry SDI-12 measurements, or separating Concurrent mode
measurements into Concurrent groups (above).
You can choose to power SDI-12 sensors from any of the other GP2 power
channels if they don't require +12V supply. If you don't want to risk power-hungry
SDI-12 sensors draining the GP2's battery, you can choose one of the GP2's relay
channels to switch an independent external power supply.
Some SDI-12 sensors are designed to be permanently powered and don't
respond well to 'power cycling' between measurements. If a manufacturer
advises against power switching, select <none> and connect the sensor to a
permanent power supply.
It is possible to power some sensors from a GP2 Power channel and others to a
permanent supply and select a Power channel or <none> accordingly. However,
only one Power channel can be used to power all SDI-12 sensors, so the selected
Power channel (if it is not <none>) applies to all SDI-12 measurements in a
program.
Warmup duration
Applies if: Power channel or Power channels (above) is not None.
For a SDI-12 sensor, the Warmup duration is the time required by the sensor to
power up, initialize and become ready to receive SDI-12 commands. It is applied
before issuing any commands to the sensor and is distinct from the Measurement
duration (s) - which is the time required by the sensor to complete a measurement
after receiving a 'start measurement' command.
SDI-12 sensors in a program may have different Warmup duration; if so, the
program allows the longest Warmup duration before issuing a command to any
sensor, to ensure all sensors are ready to receive commands.
Further information


Page 34
SDI-12 Commands on page 35.
DeltaLINK online Help.
SDI-12 Input Properties
SDI-12 Commands
When using the GP2 and DeltaLINK the only SDI-12 you must know are the
Query “?!” and Change Address “aAb!” commands – because you must first
ensure each sensor has a unique address.
In addition, the Identification command “aI!” is useful to help you identify what type
of sensor and who made it.
Apart from that the SDI12 standard includes a lot of commands about instructing
sensors to start taking readings or to send the data. Fortunately DeltaLINK knows
these commands and makes a pretty good job of shielding you from them. The
default DeltaLINK SDI-12 sensor types provided for a range of third party SDI-12
sensors should help you quickly start to take readings.
The sensor Address Query “?!” command.
This requests any sensor to send its address.
The sensor must be alone on the bus … otherwise all sensors will ‘shout at once’
and send their own address.
In the DeltaLINK Transparent mode command box type ?! followed by Enter or
click the Send button.
In the output box you see6 the following:
?!a
Command
Address
Command terminator
We would normally expect this address to be
zero for a new sensor, but it might not be.
Here the address reported is “a” (It could be a-z, A-Z or 0-9).
Terminating commands and automatic retries
SDI-12 commands sent to a sensor must end with a !
DeltaLINK will do this for you, it adds the “!” command terminator to any command
that you type.
So if you just type ? and press Enter you will see “?!” sent.
What follows the ! is the sensor’s reply, which is “0” in the example below
If the sensor does not reply quickly then
DeltaLINK will send the command again.
6
There is also a hidden <Carriage Return> <Line Feed> string at the end of each message,
which just acts to display the next reply on a new line.
SDI-12 Commands
Page 35
All commands (apart from “?!”) begin with the sensor
address
All SDI-12 commands apart from the “?!” adress query start with an address and
finish with an exclamation mark ‘!’
Change Sensor Address “aAb!”command
In this example we change the address from “0” to “P”.
In the DeltaLINK Transparent mode command box type 0AP! followed by
Enter or click the Send button.
In the output box you see7 the following:
0AP!P
Command
Reply
Command terminator
Sensor Identification “aI!” command
In this example we ask the sensor at address “P” to send its Identity.
In the DeltaLINK Transparent mode command box type PI! followed by Enter or
click the Send button.
If you were sending this to a Delta-T SDI-12 PR2 Probe at address P then in the
output box, following the PI! command, you would see the following reply:
a13Delta-T PR2SDI0020000000010001<CR><LF>
Serial number
Version
Sensor model number
Manufacturer
SDI-12 standard version 1.3
Carriage return,
Sensor address
linefeed
Note: This information is different for each sensor manufacturer
7
There is also a hidden <Carriage Return> <Line Feed> string at the end of each message,
which just acts to display the next reply on a new line.
Page 36
SDI-12 Commands
“Start Measurement” Command
The “M!” command tells a sensor to start taking measurements.
The sensor responds with the following:

Measurement duration how long the measurement will take (0 to 999 s)

Number of values that the measurement will produce (up to 9).
In this example a PR2-SDI sensor is assumed to be at address P
In the DeltaLINK Transparent mode command box type PM! followed by Enter
or click the Send button.
The output box displays:…
PM!P0016P
Command
Command terminator
Reply address
How long the measurment will take
Number of values
Service request
Other measurement commands are also available, to do with the type of
measurement. See also Concurrent measurements and CRC (Cyclic Redundancy
Checking).
“Send Data” Command
The “D0” Send Data command is sent to retrieve the results when the sensor is
ready. Other commands D1! To D9! are available for retrieving additional results if
needed.
In the DeltaLINK Transparent mode Command box type PD! followed by Enter
or click the Send button.
Typical replies are shown.
Figure 7 In this example a PD0! command is
followed by the PD1! Command.
SDI-12 Commands
Page 37
Sequential and Concurrent Measurement Commands
M! starts a ‘sequential’ measurement.

One sensor is active.

All others in low power quiescent mode
C! starts a ‘concurrent’ measurement.

Several sensors can be active and measuring at the same time

More rapid throughput

But more loading on SDI-12 power supply

… which may be a problem with high current consumption sensors

Can provide up to 99 values.
More measurement command variants…
Many sensors also provide additional measurement commands.
i.e. M1! … M9! and C1! … C9!
These provide alternative measurement methods.
Each can provide up to 9 (or 99) values.
MC! and CC! commands provide a ‘CRC’ checksum with measurement results.
This is recommended for optimizing data integrity.
Extended ‘X’ commands
M, C, and D commands are ‘standard’ SDI-12 commands.
X commands may be provided by manufacturers for configuring the sensor.
These are often used to modify behaviour of measurement commands, for
example, to change measurement units.
Manufacturers can use X commands to provide a ‘Factory reset’ command to
restore the sensor to a known configuration.
Refer to the manufacturer’s data sheets for further information.
Page 38
SDI-12 Commands
Screw terminal cabling
Unshielded screw terminal connector kits
Figure 8 Showing the parts supplied with the screw terminal kits for
use with unscreened SDI-12 sensor cables
M12 male 5-way connector kit with screw terminals and plastic shell for attaching
SDI-12 sensors which use unshielded SDI-12 sensor cable.
Two cable gland size options are available:
CON/5W-M-NS-SD In-line M12 male 5-way connector to screw terminals, with
unscreened plastic shell, for connecting SDI-12 sensors fitted with unscreened
cable to GP2 logger.
Accepts cables of 3-6.5 mm diameter.
CON/5W-M-NS-LD In-line M12 male 5-way connector to screw terminals, with
unscreened plastic shell, for connecting SDI-12 sensors fitted with unscreened
cable to GP2 logger.
Accepts cables of 4-8 mm diameter.
3
GROUND
SDI-12 DATA
SDI-12 POWER
4
4
2
5
1
3
GROUND
SDI-12 DATA
SDI-12 POWER
SCREEN (if present)
4
4
2
5
1
Figure 9 Wiring schemes used with the screw terminal kits, unshielded on the
left, shielded on the right
Screw terminal cabling
Page 39
Shielded Screw terminal connector.
CON/5W-M-S-LD
This in-line M12 male 5-way connector to screw terminals, with screened metal
shell, for connecting SDI-12 sensors fitted with screened cable to GP2 logger.
Accepts cable 4-9 mm diameter.
Figure 9 Copy of manufacturer's wiring instructions.
Figure 10 Exploded-view of an example of an SDI-12 sensor cable wired-up
using the shielded connector.
Page 40
Screw terminal cabling
Troubleshooting
Don’t get your Networks muddled
WARNING: Do not confuse the GP2 Logger to Logger Network Cabling
options with the SDI12 sensor to sensor network cabling options on page 15.
Fault Finding SDI-12
No SDI-12 sensors appear to be working on the network.
1)
2)
3)
4)
If one SDI12 sensor fails it can bring down the whole network.
Isolate each SDI12 sensor by disconnecting all others from the SDI-12 network.
Use the Transparent Mode to interrogate the one remaining sensor.
If it appears to be responding with the correct address and meta-data about itself
see if it gives sensible readings.
If the sensor appears to be working, remove it from the network and connect the
next SDI-12 sensor and repeat the above.
The isolated single SDI-12 sensor is not responding
Divide and conquer. Swap with other components that you know are working.

Check the wiring.

Check the sensor power supply.

Toggle the power supply off and on.
Some third-party sensors are known to lock up (intermittently) unless the
power is permanently on.

Check the polarity of the power supply is correct for the sensor.

Check the logger is working.
If you can prove to your satisfaction the rest of the system is working OK, then the
sensor must be faulty or incorrectly connected or incorrectly configured
Sensor unreliable if power cycles on and off.
The GP2’s internal sensor power sources help save battery life by only providing
warmup power to sensors when needed.
We have found some third-party manufacturer’s sensors (not supplied by us) are
not reliable unless powered up continuously.
Please check with the manufacturer whether it requires continuous power and if
so, you will need to provide this separately.
Troubleshooting
Page 41
Appendix 1: GP2 Relay Expansion Module
Contents
This contains:
4 x mounting screws.
4 x stand-off pillars
5 x link wire
1 x GP2 relay expansion PCB
Overview
The GP2 contains 2 relays, used as
switches. This expansion module provides 4 more, bringing the total to 6.
These can only be used with low voltage applications, not mains power.
DO NOT CONNECT 110V or 240V MAINS POWER TO THE RELAY
Each relay is protected from overvoltage and overcurrent using a resettable fuse
that will activate at 1A. The relays can handle up to 24V AC or 32V DC.
The relay expansion module fits onto the ‘EXPANSION BOARD’ position on the
GP2 PCB (as shown below).
Fitting Instructions
Warning: use anti-static procedures when handling the relay expansion
module
1.
Screw in the 4 hex stand-off pillars (provided) into the 4 positions on the
GP2 PCB
2.
Push the relay expansion module onto the GP2 PCB as shown above. The
header on the bottom of the module should fit into the ‘RELAY’ connector on
the GP2 PCB and the 4 screw holes should line up with the hex stand-off
pillars underneath.
3.
Use the 4 screws (provided) to secure the PCB down on to the GP2.
Page 42
Appendix 1: GP2 Relay Expansion Module
Relay Layout
RELAY 3
RELAY 4
RELAY 6
Note: All ‘Pwr’ and ‘Ret’ terminals are joined together on the circuit board
Power should not exceed 1A at 32V DC or 26V AC.
DO NOT CONNECT 110V or 240V MAINS POWER TO THE RELAY
How to Control the Relays
To instruct the relays to switch on or off you need to set up suitable ‘control’
conditions which meet your requirements. This is done using the DeltaLINK
program.
For more information on how to do this, please refer to the DeltaLINK online help.
You may also find the video tutorials helpful.
Appendix 1: GP2 Relay Expansion Module
Page 43
Relay Wiring - Option 1:
Power supply NOT shared by all the relays
Using more than one power supply: To use the relays to switch in various
devices where each uses a separate, different power supply then connect the
positive wire directly from the selected power supply into the relay of choice.
Do not use the ‘Pwr’ and ‘Ret’ routing options on the board:
Figure A1: Example wiring for switching on a solenoid
valve using the A and B terminals of relay number 4.
Relay terminals, applicable to relays 1 - 6
Pwr:
Not used.
A:
Connect to power supply positive (+) output
B:
Connect to pump positive (+) wire
Ret:
Not used.
Connect the pump negative (-) wire directly to the power supply negative
(–) terminal.
** DO NOT CONNECT 110V or 240V MAINS POWER TO THE RELAY **
Page 44
Appendix 1: GP2 Relay Expansion Module
Relay Wiring – Option 2:
Power supply shared by all the relays:
If you want to switch in several devices that all share the same power supply, such
as pumps or solenoids, you can use the external power option and route the power
through to each relay via the ‘Pwr’ and ‘Ret’ terminals:
• External power in (‘PWR IN’):
Pwr:
Connect to the +ive terminal on the power supply.
Ret:
Connect to the –ive terminal on the power supply.
• Relay terminals, applicable to relays 1 - 6
Pwr:
Link to the ‘A’ terminal next to it, e.g. ‘4A’
A:
As above, linked to ‘Pwr’
B:
Connect to pump +ive wire
Ret:
Connect to pump –ive wire.
Figure A2: Switching in a solenoid valve using a common power supply through
relay number 4
Figure A3: Switching in a solenoid valve using a common power supply through
relay number 1 on the main PCB.
*Warning: The relay only can take up to 1A at 24V AC or 32V DC.
** DO NOT CONNECT 110V or 240V MAINS POWER TO THE RELAY **
Appendix 1: GP2 Relay Expansion Module
Page 45
Appendix 2: GP2 Network Cabling
Figure A4. A network of 7 GP2 loggers connected to a PC via a total 100m of
EXT/5w-xx extension cables and seven M12 5-way “GP2-NTP” T-Piece
connectors. This is the maximum number of loggers and maximum cable length
supported.
Do not use GP2-STP T-pieces for connecting loggers, the STP T-piece is for SDI12 sensor networks only and won’t work with logger networks.
Page 46
Appendix 2: GP2 Network Cabling
Figure A5 GP2 Network Cabling options
Notes


A mini USB cable (not shown in Fig A5) - is required in order to configure
the modem at the logger end. This is supplied as standard with the Delta-T
modem solutions i.e. 3G-DLC-BX1/B and MD-3G-DLC.
Seven is the maximum number of loggers which can be supported on a
combined network of GP1 (and/or DL6) and GP2 loggers.
WARNINGS





Only one external power supply should ever be connected to the network.
Never connect more than one external battery.
The GP2 network serial communication and power cable should not exceed
3A or 15V DC.
Lead acid batteries must have a 2.5A in-line fuse in series with the +’ve wire
to protect the network cabling.
Do not charge any external battery (including one in the modem box) via any
extension cables.
These warnings apply to all GP2 and GP1 network cabling systems.
Appendix 2: GP2 Network Cabling
Page 47
DeltaLINK System Requirements
You need DeltaLINK version 3.2 or later.
Go to http://www.delta-t.co.uk/software/deltalink for the current version.
Creating a Network Connection
1.
2.
3.
Connect your PC to the GP2 network, via the GP2 USB cable or GP2RS232 cable, or, if using a modem, via the cabling indicated in Figure A5..
Start DeltaLINK. Select Connection Details to display a window listing all
(known) logger connections. The first time you do this the list may be empty.
In the Connections dialog, click Add… to pop up the Connection
Properties dialog. See Figure A6.
Figure A6 Connection Properties
4.
5.
6.
7.
8.
9.
10.
In Connect to logger using: select the communication method, e.g. Serial.
Select the Details tab and enter connection details e.g. COM3.
See also: How to Find your COM Port on page 49.
Select the Connection tab, tick the Networked check box, and enter the
serial number of the GP2 that you want to address.
Enter a descriptive Connection name, e.g. or “GP2 3-24 on COM3 (USB).
Click OK, and in the Connections dialog select the new connection and click
OK.
DeltaLINK will then open the connection in a new window.
Repeat the procedure for each logger on the network, with a unique
connection name for each.
Page 48
Appendix 2: GP2 Network Cabling
Figure A7 Example showing how
DeltaLINK displays connections to GP2
loggers on the network connected to a PC on
COM Port 3
How to find your USB COM port
See also: How do I set up my USB to RS232 converter?
at https://www.delta-t.co.uk/product/gp2/#support
Appendix 2: GP2 Network Cabling
Page 49
Appendix 3: Cable Expansion Lid
Note: The GP2 case has 9 cable glands for 3-6 mm diameter cables. Additional and/or
larger cables can be fitted using this expansion lid.
GP2-G5-LID
This GP2 lid has 5 general purpose cable
glands.
Each gland can accept either a cable with an
outer diameter of 3 to10mm diameter, or it can
take 2 cables of diameter 3 to 4.5mm - using a
gland insert with two holes.
See also: Appendix 7: Make sure the GP2 is properly on page 54.
Page 50
Appendix 3: Cable Expansion Lid
Appendix 4: WS-CAN Canopy
Parts
GP2
Logger
DL2e
Logger
Assembly
Appendix 4: WS-CAN Canopy
Page 51
Appendix 5: DL-MKT Universal Data Logger
Mounting Kit
The Universal Mounting Kit is a 2mm thick flat stainless-steel plate with U-bolts
suitable for attaching to a 42 mm (1⅝ inch) diameter vertical pipe or post and with
nuts and bolts for GP2, GP1 and DL6 loggers.
Page 52
Appendix 5: DL-MKT Universal Data Logger Mounting Kit
Appendix 6: M-ENCL-B2 Enclosure with
Modem Gateway to DeltaLINK Cloud
The enclosure is designed for use with the standard Delta-T M2 2m mast. It is an
alternative to the weather station canopy and provides greater weather protection,
electrical shielding, and security for GP2 logger and its related accessories.

Weatherproof to IP54 standard

Side opening door with twin locks

Gland plate with 12 cable glands

Two inch diameter pole mounting brackets (2 off)

Trunking for tidy cable routing

Earthed back plate and strap
Detail showing an M-ENCL–B2 Enclosure with
additional options installed:- top left Modem
Gateway type MD-3G-DLC, bottom left - a solar
charger regulator (which along with a 30W solar
panel and cabling forms a SOL4-KIT2, and
bottom right a 12V, 10 Ah battery type LBAT4
For further information see:

M2 Enclosure User Manual

Modem Gateway User Manual
at http://www.delta-t.co.uk.
See also:

http://www.delta-t.co.uk/DeltaLINK-Cloud.asp

www.deltalink-cloud.com
Appendix 6: M-ENCL-B2 Enclosure with Modem Gateway to DeltaLINK Cloud
Page 53
Appendix 7: Make sure the GP2 is properly
sealed.
Make sure the case is not cracked nor damaged in any way.
Check there is no dirt, foreign objects or damage to the rubber lid seal – this could
compromise the integrity.
Firmly tighten all 4 lid screws
Make sure the rubber seal in the cable
gland looks intact and clean.
Make sure the rubber seal hasn’t pealed back on
itself when a cable was inserted.
Ensure unused cable glands have a
blanking plug fitted.
Tighten cable glands onto the cable,
not onto heat shrink.
Tighten the cable glands as hard as you can
by hand or use a torque wrench set to 0.7 nm.
A cable coming out of a GP2
with bare wires exposed, or a
break in the insulation, can allow
water to enter, so ensure the
whole cable is properly sealed.
If possible use sealed
connectors and mount the logger
vertically with the cable glands
facing down.
Page 54
Appendix 7: Make sure the GP2 is properly sealed.
Appendix 8: Upgrade GP2 Firmware
1.
2.
3.
4.
5.
Identify the COM port of the USB adapter used by the GP2:
a. Start DeltaLINK 3.
b. In DeltaLINK Logger view select Connection
Details (bottom left hand corner).
c. Add or Edit the Connection and select Connect to logger using:
Serial port.
d. Select Details and Detect USB port.
e. Follow the instructions to disconnect and reconnect the USB serial
port adapter.8
f. Note the COM port number.
Check your GP2 firmware version, displayed in
DeltaLINK.
a. If it is not at version 2.10 or later proceed as
below to updgrade your firmware.
b. Close DeltaLINK.
In Windows Start menu click on “All Programs”, open the DeltaLINK 3.2
folder and start Firmware Upgrade.
Select (or type) the COM port name.
Click Upgrade
2.10
6.
Wait while the upgrade is completed, then the Firmware Upgrade
8
Slower PCs may struggle with this, if so, please use your Device Manager to identify the
COM port
Appendix 8: Upgrade GP2 Firmware
Page 55
GP2 Specifications
General Specifications
Program repeat
rate
Real time clock
Multiples of 1s
Communications
RS232 115.2kBaud, USB-RS232 adapter cable supplied
Networking
Up to 7 GP2s on 100 m of network cabling, with optional power
distribution over network cabling
Input protection
All terminals protected to ±15VDC, 24VAC, including battery reverse
polarity
Regulatory
compliance
Surge tested IEC61000-4-5 PASS A
± 1 minutes per month typical, ±5 minutes per month worst case.
(-20 to +60 °C)
ESD tested IEC61000-4-2 PASS A
EMC tested IEC61000-4-3 PASS A
CE Compliant
FCC Compliant
Environmental
Operating: -20 to +60 °C
Enclosure
Fitted with cable glands, IP65
Data storage
4 MBytes FLASH memory.
Storage capacity (compressed): 2.5 million values (typical).
Autowrap option (i.e. overwrite earliest data when memory full)
and/or manual deletion of data without interrupting logging.
Activity indicator
Every 10s, LED signals logging and error status
Page 56
GP2 Specifications
Analogue Input Specifications
Analogue
input
channels
12 differential.
Each provided with signal (+), (-) and 0V (SGND), and power (PWR) and
power return (PGND) terminals, and individually configurable for
differential voltage, 3-wire resistance, bridge, potentiometer, or for a pair
of single-ended voltage or 2-wire resistance measurements (up to 24 in
total).
Input ranges
4 ranges, -1.4V to 2.7V maximum
Auto-ranging
Optional, adaptive
Sensor
source
impedance
Sensor
excitation
<11K source resistance
<20nF source capacitance
Open circuit
detection
Optional, (+) and (-) terminals biased to -5V and +5V respectively for 2 ms
via 50KΩ prior to the measurement
Settling time
Optional, 1 to 200 ms for high value resistance measurements
Reading
duration
Per analogue measurement:
6ms built-in settling time
+ 2ms if open circuit detection enabled
+ optional settling time
+ 20ms or 16.67ms depending on mains filter frequency
+ additional 20 or 16.67ms if 2nd auto-range cycle required
Plus, per program execution cycle:
20 ms startup
+ 2 to 8 self-calibration cycles of 11ms
(dependent on mix of required measurements)
+ 26ms resistance self-calibration if required
Noise
rejection
Common mode rejection ratio: >70 dB
Common mode range: +3V to -2.5V
For Bridge measurements, common mode nulled at +1.5V.
Normal mode mains rejection (50/60Hz):
20uA current source for resistance and precision 3V for bridge and
potentiometric measurements provided at each terminal cluster.
100 - 60dB (0 to 0.1% mains frequency error)
Input
leakage
Input
resistance
Stability
<2nA typical (-20 to +60°C: <12nA)
Cold junction
thermistor
Built-in, 0.1°C precision 10K Thermistor + logger contribution as below.
Isothermality <0.1°C per 1°C per hour temperature change
0.8 to 3.8 GΩ
0.02% worst case over 1 year
Recalibration recommended every 2 years
GP2 Specifications
Page 57
Analogue Accuracy
Input range
GP2 at 25 ° C
-20 to +60 °C
Noise*
-0.17V to 2.7V
0.004% + 87µV
0.036% + 148µV
33 µV
-1.4V to 1.5V
0.004% + 87µV
0.036% + 148µV
33 µV
±185mV
0.008% + 17µV
0.067% + 38µV
5.9µV
±23mV
0.024% + 13µV
0.09% + 31µV
4.3µV
-1.7V to 2.7V
0.007% + 86µV
0.043% + 119µV
33 µV
-1.4V to 1.5V
0.007% + 86µV
0.043% + 119µV
33 µV
±185mV
0.013% + 11µV
0.076% + 25µV
5.9µV
±23mV
0.017% + 9 µV
0.084% + 22 µV
4.3µV
135KΩ
0.045% + 4.15Ω
0.138% + 6.46Ω
1.6 Ω
9KΩ
0.059% + 0.63Ω
0.184% + 0.93Ω
0.3 Ω
1KΩ
0.091% + 0.42Ω
0.229% + 0.28Ω
0.2 Ω
Resistance
2-wire
135KΩ
0.045% + 15.4Ω
0.109% +22.9Ω
1.6 Ω
9KΩ
0.052% + 11.8Ω
0.155% + 17.4Ω
0.3 Ω
Bridge
±62mV/V***
0.037% + 20µV/V
0.077% + 48µV/V
2 µV/V
±7.5mV/V
0.053% + 15µV/V
0.100% + 41µV/V
1.5 µV/V
0 to 1
0.036% + 0.00015
0.057% + 0.00017
36 µV or
Voltage
differential
Voltage **
single-ended
Resistance
3-wire
Potentiometer
0.00002%
Thermistor
(3-wire)
10K, -20 to +60°C 0.04°C
0.08°C
<0.01°C
2K, -20 to +60°C
0.05°C
0.09°C
<0.01°C
0.47°C
1°C
<0.3°C
Thermocouple**** ±23mV
K type
(differential)
* RMS noise, included in offset figure
** Single-ended voltage measurements are subject to further offset errors due to current
flowing in signal ground.
*** mV per 1V excitation
**** GP2 contribution to measurement error only, sensor error is additional
Page 58
GP2 Specifications
Digital Input Specifications
Counter/frequen
cy/digital state
channels
SDI-12 sensors
WET sensor
2 x fast, 30 kHz, 30 us debounce
2 x slow, 100 Hz, 5 ms debounce
Accepts logic level (low <0.8V, high >2.4V) or open collector or
voltage-free switch closure inputs.
Up to 62 SDI-12 sensors9. Limited by 300 measurements, max cable
length and GP2 memory.
1 x WET sensor channel (see footnote 4).
Water content, bulk/pore conductivity and temperature.
Relay Outputs
Relay channels
Type
2 plus 4 with optional relay expansion card
Latching, single pole single throw
Rating
Functions
24VAC, 32VDC, 1A thermal fuse overload protection
Alarm, control, scripts, or switching power to sensors
Other
Dimensions
Weight
Package
contents
Warranty
225 x 185 x 75 mm (Standard lid, no
cables)
1 kg (Standard lid, No packaging, No
relay PCB)
GP2 logger with lid
Desiccant and desiccant storage bag
Toolkit- spanner and screwdriver
GP2 User Manual
2 years
9
The serial input channel can be connected to either one WET sensor or to an SDI-12 sensor
network, but not both at the same time.
GP2 Specifications
Page 59
Power Supply Specifications
Internal
battery
External
power
6 x AA alkaline cells
Mains
adapter
Sleep
current
Accessory, provides 12VDC regulated, 2.5A
Wake
current
Backup
<10 mA, plus any current supplied to sensors
Low power
detection
3.09V to 3.42V shutdown to self-preservation mode
4.1 V analogue readings fail
User defined minimum power for analogue measurements
powered via PWR Bank A or B (below). Measurements invalidated if
requirement not met.
IN: 10 to 15VDC, 2A via screw terminals or network cabling
OUT: 2.5A via network cabling
< 60uA typical (-20 to +60 °C: 120uA)
Plus 30uA for each digital input held low.
<1mA (input regulator current) when running from external power
supply unit
GP2 draws current from internal battery or external supply,
whichever provides the higher voltage, so internal battery serves as
backup supply if external power fails. Internal backup capacitor
retains program state and maintains the clock for >1 hour for
battery change or if both supplies fail.
Sensor Power and Warm-up Specifications
Any of the sources below can be selected for powering sensors. Power is switched
when required, either immediately before a measurement or with 1s to 60s warmup duration in advance.
PWR Bank
A
PWR Bank
B
REF 3V
Banks A, B
5 to 10.5 V unregulated, 180 mA. Routed to PWR terminals of analogue
input channels CH1 to CH6.
As PWR Bank A, routed to CH7 to CH12
WET PWR
+5V
Calibrated 3V reference for bridge and potentiometer excitation,
±0.2 mV (-20 to +60: ± 0.9mV) 18mA. Routed to Bank A and B terminals, so
excludes use of PWR on the selected Bank.
5 to 10.5V, 50 mA min, 150mA max unregulated
5.0VDC ±2% (-20 to +60: ±3%), 50mA, shared with internal functions
+12V
Relays
RLY 1 to 6
12 ± 0.4VDC (-20 to +60: ±0.6VDC), 0.5A
Relay can be configured switch power to sensors from an independent
external supply.
Page 60
GP2 Specifications
DeltaLINK 3 Software Specifications
DeltaLINK 3 is Windows software for configuring, managing and downloading data
from the GP2 data logger
System requirements
Screen
Operating
system
1024 x 600 or more
MS Windows XP SP3 or later
Features
Compatibility
GP2 (GP1, DL6 data loggers – see footnote10)
Logger status
Program
settings
Command line
tool
Logger, program, memory and battery status, and error log.
Modify selected aspects of program behaviour without
interrupting program execution.
Measurement values charted on demand at any time, for
setting up and checking that ‘all is well’
Chart and table views of downloaded data, export as text file.
Caching to optimize download times of large datasets
Multifunction GP2 program editor displays the logging program,
with point and click programming interface (GP2 loggers only).
Detailed context-sensitive Help and reference.
This can simulate a GP2 which is logging Delta-T sensors and
operating irrigation valves in a mid-latitude maritime climate.
For experimenting with program outcomes.11
Downloads and manages logged data and error log. Can run in a
Windows scheduled task to automate data download.
Document
library
Folder containing rich product documentation and application
note resources
Firmware
update
Update to most recent firmware version
On demand
measurements
Data
download
Program editor
Online help
GP2 simulator
10
11
Software support for DL6 and GP1 loggers uses earlier version of DeltaLINK
The Simulator does not support SDI-12 sensors.
GP2 Specifications
Page 61
Multifunction GP2 Program Specifications
Measurements
Input types
Calculation
methods
Delta-T sensor
library
Custom
sensor library
Recordings
Controls
Alarms
Scripts
Variables
Program
settings
Video tutorial
Page 62
Analogue, digital, and calculated measurements.
Unlimited number (subject to channel availability and program
size).
Individually configured for input type, calculation method and result
limits, or by selection of a sensor type from a sensor library picking
list.
Voltage, resistance, current, bridge, potentiometer, counter,
frequency, digital state, WET.
No calculation, average, min., max., mean, sum, linear scaling, slope
and intercept, linearization table, comparator, thermocouple, soil
moisture, pore conductivity and custom formulae.
Delta-T sensor library provides sensor types for all GP2-compatible
Delta-T line item sensors, including detailed HTML Sensor
configuration notes.
User-defined custom sensor library, including configuration notes
created with built-in HTML editor.
Individual readings, statistics, total, integral, wind (including
direction and vector average, gust, wind roses), conditional
Relay switching controlled by independent Activate and Rest
conditions, safety conditions (limit duration of Active and Rest
periods), with optional additional recording while Active, and
optional pulsing. Conditions expressed as custom formulae and
evaluated at defined repeat rates or on a digital event or on a
DeltaLINK button click.
Relay switching triggered by evaluation of a measurement and
comparison against a numeric threshold value(s) or a custom
formula. Optional pulsing.
Custom scripts, executed at a defined repeat rate, including
conditional branches (IF… ELSEIF…ELSE…ENDIF), recording,
switching relays and use of variables.
For use in custom formulae and scripts
Variables and critical control parameters optionally configured to
be adjusted while the program runs.
Instructions for building up a sophisticated program in easy stages.
GP2 Specifications
Script Editor Specifications
Point and click user interface for constructing custom formulae and scripts
incorporating the following programming elements:
Statements *
IF… ELSEIF…ELSE…ENDIF, RECORD, ASSIGN
Values
Constants (number, integer, time, duration), variables,
measurements, outputs
Arithmetic: +, –, *, /, %
Logical: ==, <>, >=, <, <=, AND, OR
IsNumber, IsNan, IsOverflow, IsUnderflow
Operators
Numeric
status
Mathematical
functions
Time and date
Minimum, Maximum, Average, Sum, Sin, Cos, Tan, ASin, ACos,
Atan, SinH, CosH, Ln, Log10, Exp, Pow, Abs, Atan2
NOW, Time, Day of month, Month, Day of Week, Day of Year,
Week of Year, Week of Month, Year
* Statements are applicable only in scripts. Other elements may not be applicable, depending
on the context.
Simulator Specifications
The simulator assists the development of logging and control programs, simulating a
temperate maritime climate at a latitude of 51 degrees North, such as that in the UK.
Soil water, nutrient and heat fluxes are simulated.
Soil moisture is lost by drainage and by surface evaporation and evapotranspiration from a spring-sown crop harvested in the autumn.
Water uptake peaks in high summer, nutrient uptake peaking earlier.
Soil water is replenished by rainfall, and by irrigation which is modelled by switching
the GP2’s relays.
Irrigation can be with fresh water or saline/nutrient solution – these differ in their effect
on soil salinity – and can be measured by a simulated flow meter.
The simulator can be speeded up and the same weather pattern can be repeated.
SDI-12 sensors are not currently supported in the simulator.
For full details please see DeltaLINK 3 Help.
GP2 Specifications
Page 63
Product Care and Maintenance
The battery can be changed quickly without losing program settings or data, but no
additional data will be logged while the battery is removed. Change the battery if the
voltage indicated on the Logger window of DeltaLINK is under 5.5V or below the
supply voltage needed for sensors.
One 25g bag of desiccant protects the logger from condensation. Replace with fresh
desiccant annually to ensure continued logger accuracy and reliability. Keep the cover
on and cable glands sealed except when connecting sensors or changing the battery.
Logger sealing: See Appendix 7: Make sure the GP2 is properly on page 54.
The Service Kit (GP2-SER) contains desiccant, a replacement battery holder, spare
M8 connector cover cap & lanyard, and spare sealing bungs.
GP2 Calibration Certificate
To see your current calibration certificate:  Connect your PC to your GP2.




Select Windows Start menu icon
, All
Programs, Delta-T Devices, DeltaLINK 3 menu
and run GP2 Calibration Certificate Generator
Enter the number of your GP2 COM port
connection and, if networked, the GP2 serial
number
Select Fetch Details from logger.
Select Save or Print Certificate as required.
Legal and Regulatory Advice
Please read GP2 Product Usage.pdf in the DeltaLINK 3\Document Library folder.
The GP2 is CE compliant, conforming to the essential requirements of EMC directive
2004/108/EC.
For US markets the GP2 is Part 15 FCC compliant.
Page 64
Product Care and Maintenance
Warranty and Service
Terms and Conditions of Sale
Our Conditions of Sale (ref: COND: 1/07) set out Delta-T's legal obligations on
these matters. The following paragraphs summarise Delta T's position, but
reference should always be made to the exact terms of our Conditions of Sale,
which will prevail over the following explanation.
Delta-T warrants that the goods will be free from defects arising out of the
materials used or poor workmanship for a period of two years from the date of
delivery.
Delta-T shall be under no liability in respect of any defect arising from fair wear
and tear, and the warranty does not cover damage through misuse or inexpert
servicing, or other circumstances beyond their control.
If the buyer experiences problems with the goods they shall notify Delta-T (or
Delta-T’s local distributor) as soon as they become aware of such problem.
Delta-T may rectify the problem by replacing faulty parts free of charge, or by
repairing the goods free of charge at Delta-T's premises in the UK during the
warranty period.
If Delta-T requires that goods under warranty be returned to them from overseas
for repair, Delta-T shall not be liable for the cost of carriage or for customs
clearance in respect of such goods. However, Delta-T requires that such returns
are discussed with them in advance and may at their discretion waive these
charges.
Delta-T shall not be liable to supply products free of charge or repair any goods
where the products or goods in question have been discontinued or have become
obsolete, although Delta-T will endeavour to remedy the buyer’s problem.
Delta-T shall not be liable to the buyer for any consequential loss, damage or
compensation whatsoever (whether caused by the negligence of the Delta-T, their
employees or distributors or otherwise) which arise from the supply of the goods
and/or services, or their use or resale by the buyer.
Delta-T shall not be liable to the buyer by reason of any delay or failure to perform
their obligations in relation to the goods and/or services if the delay or failure was
due to any cause beyond the Delta-T’s reasonable control.
Warranty and Service
Page 65
Service, Repairs and Spares
Users in countries that have a Delta-T distributor or technical representative
should contact them in the first instance.
Spare parts for our own instruments can be supplied and can normally be
despatched within a few working days of receiving an order.
Spare parts and accessories for products not manufactured by Delta-T may have
to be obtained from our supplier, and a certain amount of additional delay is
inevitable.
No goods or equipment should be returned to Delta-T without first obtaining the
return authorisation from Delta-T or our distributor.
On receipt of the goods at Delta-T you will be given a reference number. Always
refer to this reference number in any subsequent correspondence. The goods will
be inspected and you will be informed of the likely cost and delay.
We normally expect to complete repairs within one or two weeks of receiving the
equipment. However, if the equipment has to be forwarded to our original supplier
for specialist repairs or recalibration, additional delays of a few weeks may be
expected. For contact details see below.
Technical Support
Users in countries that have a Delta-T distributor or technical representative
should contact them in the first instance.
Technical Support is available on Delta-T products and systems. Your initial
enquiry will be acknowledged immediately with a reference number. Make sure to
quote the reference number subsequently so that we can easily trace any earlier
correspondence.
In your enquiry, always quote instrument serial numbers, software version
numbers, and the approximate date and source of purchase where these are
relevant.
Contact Details:
Tech Support Team
Delta-T Devices Ltd
130 Low Road, Burwell, Cambridge CB25 0EJ, UK
e-mail: [email protected]
web: www.delta-t.co.uk
Tel: +44 (0)1638 742922
Fax: +44 (0)1638 743155
Page 66
Warranty and Service
Index
2K Thermistor, 12
3V precision reference, 5
Additional, 32
Address, 20, 32
analogue, 5, 9
Analogue Accur, 58
Analogue Input Specifications, 57
Apply, 12
battery power, 5
blanking plug, 54
cable glands, 54
COM port, 49
Concurrent, 32
Connect to GP2, 10
Connection Details,, 10
Connector tightening, 15
counter channels, 5
CRC, 33
DeltaLINK, 10
DeltaLINK 3 Software Specifications, 61
DeltaLINK Cloud, 53
Digital Input Specifications, 59
DL-MKT, 4
DL-MKT Universal Data Logger Mounting
Kit, 52
Event Channels, 9
Excel, 14
Expansion Lid, 50
EXT/5W-xx, 4
Firmware Upgrade, 10
GP2 Program Specifications, 62
GP2 Relay Expansion Module, 42
GP2 Simulator, 12
GP2-G5-LID, 4, 50
GP2-NPC, 4
GP2-NTP, 4
GP2-RLY, 4
GP2-RS232, 4
GP2-STP1, 4
GP2-USB, 4
Help, 11
Individual reading, 13
Info Panel, 13
Install, 10
Index
Legal Notices, 64
Logged Data, 14
M2 Lockable Enclosure, 53
M2-ENCL, 4
Maintenance, 64
Measurement duration, 33
Measurement list, 13
Measurement number, 33
measurements
mathematical, virtual, 5
Mode, 32
Modem Gateway, 53
Network Cabling, 46
Network Cabling options, 47, 48
Network Power Cable, 4
power, 4
Power, 9, 34
Power Bank, 10
Power supply NOT shared by all the
relays, 44
Power supply shared by all the relays, 45
Power Supply Specifications, 60
Product Care, 64
Program, 12
readings
maximum number, 5
Recording, 13
recording rates, 5
recording types
statistical, 5
relay, 5
Relay Channels, 9
relay expansion module, 5, 10
Relay Outputs, 59
Relay Wiring, 44
Retrieve, 14
RS232, 4
screw terminal connector kit, 39, 40
Script Editor Specifications, 63
SDI-12, 15
SDI-12 Commands, 35
SDI-12 units, 34
SDI-12 wiring, 17
Send Data, 33
Page 67
sensor
reading rate, 5
Sensor Power and Warm-up
Specifications, 60
Sensors tab, 13
serial, 4
serial input, 5
simulator, 6, 13, 63
Specifications, 56
Status LED, 9
Transparent mode, 20
Troubleshooting, 41
Page 68
tutorials, 6
USB, 4
Value, 33
variables, 6
Video Tutorials, 11
Warmup, 34
WET sensor, 5, 10
Wiring, 17
Wiring Instructions, 11
WS-CAN, 4
WS-CAN Canopy, 51
Index
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