Solinst AquaVent SDI-12 User manual

SDI-12 User Guide
AquaVent
July 1, 2020
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SDI-12 User Guide for AquaVent - Table of Contents
1 Introduction 5
1.1 SDI-12 Interface 5
1.2 LED Status 6
2 AquaVent Independent Recording Option 7
2.1 Data Downloading and Programming in Field 7
3 AquaVent SDI-12 Setup 8
3.1 Setting the SDI-12 Device Address 8
3.2 AquaVent SDI-12 Installation 10
4 Aquavent SDI-12 Operation 11
4.1 The SDI-12 Address 11
4.2 Activation and Verification 11
4.4 Changing SPX Wellhead Batteries 12
4.5 AquaVent Firmware Upgrades 12
5 SDI-12 Supported Commands 13
5.1 Acknowledge Active Command: a! 13
5.2 Address Query Command: ?! 13
5.3 Send Identification Command: aI! 13
5.4 Change Address Command: aAb! 14
5.5 Start Measurement Command: aM! 14
5.6 Start Measurement Command with Checksum: aMC! 14
5.7 Send Data Command: aD0! 14
5.8 Start Concurrent Measurement Command: aC! 14
5.9 Start Concurrent Measurement with Checksum: aCC! 15
5.10 Start Verification Command: aV! 15
6 Troubleshooting 16
7 References 17

SDI-12 User Guide for AquaVent
Page 5
1 Introduction
SDI-12 (Serial Data Interface at 1200 Baud) is a communications protocol
designed to allow the interfacing of a number of low power analog sensors with
a common SDI-12 recorder or datalogger (master). The current AquaVent 5
and previous AquaVent loggers are able to act as an SDI-12 Sensor in an
SDI-12 network simply by using the AquaVent 5 SPX Wellhead or
AquaVent SPX Wellhead, and SDI-12 Connector Cable.
Note: As features differ slightly between models, it is recommended to use
the AquaVent 5 SPX Wellhead with an AquaVent 5 logger.
The SPX Wellhead (translator) converts SDI-12 commands to the Solinst
communications protocol for the AquaVent. The SPX Wellhead and SDI-12
Connector Cable provide a hardware and protocol conversion interface between
a Solinst AquaVent and an SDI-12 network.
1.1 SDI-12 Interface
Solinst 2-wire signals are converted to SDI-12 signals by the SPX Wellhead.
The SDI-12 Connector Cable, plugged into the side of this Wellhead, has
three wires which connect to an SDI-12 master. These wires are colour-coded
according to Table 1-1.
The bottom of the Wellhead connects to an AquaVent logger through a Vented
Cable. The AquaVent logger contains a small battery, used only for memory and
clock back-up. The Wellhead contains four user-replaceable 1.5 V AA lithium
batteries that power the AquaVent logger.
The SDI-12 interface circuitry requires the +12V connection to be powered by
customer equipment. The current draw from the 12 volt source normally peaks
at several 10’s of mA, but idles around 30 uA. Upon initial power-up, or after
disconnecting from Levelogger PC Software, the Wellhead draws about 3 mA
from the SDI-12 equipment, while waiting to connect to the SDI-12 network.
After the first SDI-12 command is received, the Wellhead idles around 30 uA.
NOTE
For more information about the
AquaVent loggers, Wellheads and
Vented Cables, see the Vented
Dataloggers User Guide.
Wire Colour SDI-12 Function Connection
Red 12 Volt Line +12V DC at SDI-12 Master
Black Ground Line Ground at SDI-12 Master
White Serial Data Line SDI-12 Data at SDI-12 Master
Table 1-1 SDI-12 Interface Cable Wire Definitions
The communication settings for the SPX Wellhead hardware comply with the
SDI-12 standard at 1200 baud, 1 start bit, 7 data bits, 1 parity bit (even parity),
and 1 stop bit.

SDI-12 User Guide for AquaVent
Page 6
1.2 LED Status
The 3500 AquaVent SPX Wellhead contains a multicolour LED.
The Yellow LED flashes whenever the AquaVent replies to a data
recorder command on the SDI-12 network. The Yellow LED does not
flash when it receives a command, only when it replies to a command.
The following will also occur:
Tricolour spin (3 cycles) to indicate a power-on event.
Alternating Yellow/Green for 10 rapid cycles to indicate that AquaVent
communication has been established, the SDI-12 device address has
been set to represent that AquaVent and SDI-12 interface is online.
Alternating Yellow/Red for 10 rapid cycles would instead mean that
communication was NOT established, so the SDI-12 interface has been
brought online using the default device address of ASCII ‘0’. (Check the
batteries and the AquaVent logger connections).
Technical Specications
Standard Compliance: SDI-12 Protocol, Version 1.3, July 18, 2005, except 'A' command
Maximum Sample Rate: 1 SDI-12 sample every 3 seconds with AquaVent not logging.
+12V Input: 9.6VDC to16.0VDC
Supply Current: Normally peaks at several 10’s of mA, but idles around 30 uA.
SDI-12 Connector Cable Length: 4.5 m (15 ft)
Maximum Vented Cable Length: 150 m (500 ft)
Wellhead Operating Temperature: -20ºC to 80ºC
Wellhead IP Rating: IP 64 (dust and splash resistant)
Table 1-2 SDI-12 Technical Specifications

SDI-12 User Guide for AquaVent
Page 7
2 AquaVent Independent Recording Option
The AquaVent logger has the ability to record and store readings in its internal
memory, independent from the SDI-12 network, while connected to an SDI-12
master. Before connecting the AquaVent to the SDI-12 master, it can be
programmed and started using Solinst Levelogger PC Software (see Figure 3-1).
All standard sampling options provided by Solinst Levelogger PC Software are
available while the AquaVent is operating as an SDI-12 sensor. The AquaVent
logger can be set to record at a user-defined sampling rate; event, linear, and
scheduled sampling modes are available. This allows the AquaVent logger to
provide back-up data if the SDI-12 network fails. The AquaVent logger stores
the data in its internal memory, until it is downloaded.
If you program the AquaVent logger at a similar interval to the SDI-12 recorder,
it may require an occasional measurement retry by the recorder if the AquaVent
happens to be busy at that moment. You can change the schedule of either to
ensure this does not happen.
Each time the SDI-12 master asks the AquaVent for a current reading, the
Wellhead batteries are used to transmit the information from the logger to the
Wellhead. The AquaVent logger will also be using the batteries if programmed
to record independently – draining the batteries more quickly.
2.1 Data Downloading and Programming in Field
If the AquaVent logger has been programmed to record on its own independent
schedule, data can be downloaded from the AquaVent using a laptop and
USB Connector Cable in the field (see Figure 3-1). Temporarily disconnect the
AquaVent from the SDI-12 Connector Cable, preferably in between recordings
by the SDI-12 master. Connect a laptop and download the independently
recorded data.
If the AquaVent is disconnected from the SDI-12 network, and the SDI-12
master tries to communicate with the AquaVent, the SDI-12 master and the rest
of the sensors in the network are not disrupted.
After the data download is complete, the AquaVent is easily connected back into
the SDI-12 network without disruption. The AquaVent is automatically verified
when reconnected (see Section 4.2).
NOTE
See the Vented Dataloggers User
Guide for detailed AquaVent
operating instructions.
NOTE
Once you are finished
programming your AquaVent,
unplug the USB Connector Cable
from the Wellhead. The Wellhead
only communicates with the SDI-
12 network when just the SDI-12
Connector Cable is connected.
NOTE
The Wellhead batteries will drain
more quickly if the AquaVent logger
is also set to record independently.
NOTE
Other downloading options
are available using the Solinst
Levelogger App and DataGrabber.
See separate operating instructions.

SDI-12 User Guide for AquaVent
Page 8
SPX
Wellhead
USB Connector Cable
Vented
Cable
AquaVent 5
Logger
3 AquaVent SDI-12 Setup
3.1 Setting the SDI-12 Device Address
As the SPX Wellhead acquires its identity from the AquaVent logger, in the
absence of a functional AquaVent logger, or without setting a specific address, the
Wellhead will power up with a default address of "0".
To set the device address for the AquaVent logger, it must be connected to the
Levelogger PC Software. The AquaVent communicates with the Software using
a USB Connector Cable connected to the SPX Wellhead. The USB Connector
Cable connects to the 10-pin (Solinst Protocol) connector on the Wellhead.
NOTE
For information on downloading
and starting the Levelogger
PC Software, see the Vented
Dataloggers User Guide.
NOTE
The SDI-12 Connector Cable can
remain in place while programming
the AquaVent logger.
Figure 3-1 Communicating with Levelogger Software

SDI-12 User Guide for AquaVent
Page 9
After you start Levelogger Software, the Main Window will appear, with the
Datalogger Settings tab open.
Figure 3-2 Dataloggers Settings Tab
Select the appropriate device from the centre Com Port drop-down menu.
Click to retrieve the current settings from the connected AquaVent logger.
After you have retrieved the settings of the connected AquaVent, the Datalogger
Settings tab will identify the Instrument Type, Serial Numbers, Firmware
Versions, Project ID, Location, the Channel Settings and battery level.
Here, you can set the SDI-12 Address. The address can be customized to any
value from “0” to “9”, “A” to “Z”, or “a” to “z”, giving a total of 62 unique
addresses.
You can also change the units that the AquaVent will be measuring in for the
Level and Temperature Channels.
Once you have set the address and any other desired settings, click the start
button .This applies the address and settings to the datalogger, AND starts
the AquaVent logging internally.
If you do not want your AquaVent to log internally, independent of SDI-12
operation, click the stop button .
(See Section 2 for more information on the independent recording option).
NOTE
Once you are finished
programming your AquaVent,
unplug the USB Connector Cable
from the Wellhead. The Wellhead
only communicates with the SDI-
12 network when just the SDI-12
Connector Cable is connected.

SDI-12 User Guide for AquaVent
Page 10
Figure 3-3 AquaVent SDI-12 Installation
Wire Connections
to SDI-12
Master
SDI-12
Connector Cable
3.2 AquaVent SDI-12 Installation
1) Be sure that an AquaVent logger is properly connected to the SPX Wellhead
using a Vented Cable.
2) Turn off the power to the SDI-12 master and/or the SDI-12 network.
3) From the SDI-12 Connector Cable, take the black ground wire and connect
it to the master ground terminal; take the white signal wire and connect it to
the SDI-12 data signal wire of the master; take the red wire and connect it to
the 12 VDC power supply of the master or SDI-12 network.
4) Be sure the SDI-12 Connector Cable is connected to the SPX Wellhead.
(Ensure you have unplugged the USB Connector Cable after programming
the AquaVent with Levelogger Software).
5) Turn on power to the SDI-12 master and/or the SDI-12 network such that
power is applied to the SDI-12 Connector Cable. The SPX Wellhead LED
should emit the following signals in order:
• Tricolour spin (3 cycles) to indicate a power-on event.
• Alternating Yellow/Green for 10 rapid cycles indicate that AquaVent
communication has been established, the SDI-12 device address has
been set to represent that AquaVent, and the SDI-12 interface is
online.
• Alternating Yellow/Red for 10 rapid cycles means that
communication was NOT established, so the SDI-12 interface has
been brought online using the default device address of ASCII ‘0’.
(Check the AquaVent logger connections).
6) The SPX Wellhead and the AquaVent logger are physically and properly
hooked up to the SDI-12 master and the SDI-12 network.
NOTE
See the Vented Dataloggers User
Guide for detailed AquaVent
installation Instructions.
SPX
Wellhead
Vented
Cable
AquaVent 5
Logger