Xylem H-4280 User Manual

Model

H-4280

8-Channel SDI-12 Analog Input Module

Owner's Manual

Version 1.0

75 West 100 South, Logan, Utah 84321 Phone: [phone] Fax: [phone] Web: http://www.waterlog.com E-mail: [e-mail]

D E S I G N A N A L Y S I S A S S O C I A T E S , I N C .

75 West 100 South, Logan, Utah 84321 Phone: [phone] Fax: [phone] Web: http://www.waterlog.com E-mail: [e-mail]

D E S I G N A N A L Y S I S A S S O C I A T E S , I N C .

User Agreement/

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1. NATURE OF THE PRODUCT

This agreement accompanies an electronic sensor system comprising firmware, circuitry and other
electronic equipment in an enclosed housing, and packaged together with written instructional materials.
The packaged electronic circuitry and instructional materials herein are collectively referred to as the
“PRODUCT.” The PRODUCT is made available from DESIGN ANALYSIS ASSOCIATES, INC., of
75 West 100 South, Logan, Utah 84321 (hereinafter referred to as “DESIGN ANALYSIS”), and contains
information and embodies technology that is confidential and proprietary to DESIGN ANALYSIS, and the
availability and use of the PRODUCT is extended to you, the USER, solely on the basis of the terms of
agreement which follow.

2. ACKNOWLEDGMENTS BY USER

Opening the package which encloses the accompanying PRODUCT indicates your acceptance of the terms
and conditions of this agreement and constitutes an acknowledgment by you of the confidential and
proprietary nature of the rights of DESIGN ANALYSIS in the PRODUCT.

3. DUTIES OF YOU, THE USER

In consideration for the access to and use of the PRODUCT extended to you by DESIGN ANALYSIS and
to protect the confidential and proprietary information of DESIGN ANALYSIS, USER agrees as follows:

LOG® Warranty

(a) USER agrees that they will not remove from the exterior of the housing of the PRODUCT

any safety warnings or notices of proprietary interest placed thereon by DESIGN
ANALYSIS.

(b) USER agrees that they shall not disassemble or otherwise reverse engineer the

PRODUCT.

(c) USER agrees to treat the PRODUCT with the same degree of care as USER exercises in

relation to their own confidential and proprietary information.

4. TERM

USER may enjoy these rights only as long as their possession of the PRODUCT shall continue to be
rightful. These rights will cease if the PRODUCT is returned to DESIGN ANALYSIS under the terms of
any redemption offer, warranty, or money-back guarantee, or if USER transfers the PRODUCT to another
party on terms inconsistent with this agreement.

5. LIMITED WARRANTY
(b) What is Covered

DESIGN ANALYSIS warrants that for a period of twelve months from the time of purchase the
functions to be performed by the PRODUCT will be substantially in compliance with USER
documentation. DESIGN ANALYSIS also warrants that the PRODUCT will be free from defects
in materials and workmanship for a period of ONE YEAR from the date of purchase.

(b) What USER Must Do

If the product fails to satisfy the above warranty, USER must notify DESIGN ANALYSIS in

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writing within the applicable period specified above and reasonably cooperate with the directions
they received from DESIGN ANALYSIS.

(c) What DESIGN ANALYSIS Will Do

DESIGN ANALYSIS will repair the PRODUCT or will endeavor to provide a replacement of
same within a reasonable period of time. In the event that DESIGN ANALYSIS is unable to make
the necessary repairs or replacement within a reasonable period of time, the original purchase price
will be refunded upon the return of the PRODUCT to DESIGN ANALYSIS.

(d) Limitations

(i) THE ENTIRE REMEDY FOR BREACH OF THIS LIMITED WARRANTY

SHALL BE LIMITED TO REPLACEMENT OF THE DEFECTIVE
PRODUCT OR REFUNDING OF THE PURCHASE PRICE, AS SET FORTH
ABOVE. IN NO EVENT WILL THE LIABILITY OF DESIGN ANALYSIS
TO USER OR TO ANY OTHER PARTY EXCEED THE ORIGINAL
PURCHASE PRICE OF THE PRODUCT, REGARDLESS OF THE FORM OF
THE CLAIM.

(ii) EXCEPT FOR THE EXPRESS WARRANTIES ABOVE, DESIGN ANALYSIS

SPECIFICALLY DISCLAIMS ALL OTHER WARRANTIES, INCLUDING,
WITHOUT LIMITATION, ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

(iii) UNDER NO CIRCUMSTANCES WILL DESIGN ANALYSIS BE LIABLE

FOR SPECIAL, INCIDENTAL, CONSEQUENTIAL, INDIRECT, OR ANY
OTHER DAMAGES OR CLAIMS ARISING FROM THE USE OF THIS
PRODUCT, THIS INCLUDES LOSS OF PROFITS OR ANY OTHER
COMMERCIAL DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES. IN NO EVENT WILL DESIGN ANALYSIS BE LIABLE
FOR ANY CLAIMS, LIABILITY, OR DAMAGES ARISING FROM
MODIFICATION MADE THEREIN, OTHER THAN BY DESIGN
ANALYSIS.

(iv) THIS LIMITED WARRANTY GIVES USER SPECIFIC LEGAL RIGHTS.

USER MAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM STATE
TO STATE. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW
LONG AN IMPLIED WARRANTY LASTS OR THE EXCLUSION OF
INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THOSE
LIMITATIONS OR EXCLUSIONS MAY NOT APPLY.

6. GOVERNING LAW

This Agreement and its validity and interpretation shall be governed by the laws of the State of Utah,
notwithstanding any choice of law rules of Utah or any other state or jurisdiction.

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LOG® Warranty

H-4280

Chapter 1

Introduction

1.0 Introduction

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LOG® Model H-4280 is a 12-bit, 8-channel, analog input module. The module is an intelligent

SDI-12 “sensor” and can provide measurement data in engineering units such as feet or meters.

The H-4280 is easy to use and works with any data recorder/logger with a SDI-12 interface. The module
is powered from the +12V wire of the 3-wire SDI-12 bus. The SDI-12 (Serial Digital Interface 1200–baud)
is ideal for data logging applications with the following requirements:

 Battery powered operation with minimal current drain
 Measurement data is transmitted digitally over long cable lengths without error
 Multiple sensors on a simple three-wire cable
 Up to 250 feet of cable between a sensor and the data recorder (Use of a H-423, SDI-12

to RS485 or H-4500 fiberoptic media converter extends the range to 1000's of feet)

The H-4280 has the following features:

 Works with any SDI-12 compliant data logger
 8-analog input channels
 Supports unipolar (0-5V), bipolar (±5V) and differential (0-5V & ±5V) operation.
 12-bit A/D makes up to 700 measurements per second
 Precision 5.0V reference output for sensor excitation
 Sensor warmup time (excitation) is programmable
 Low power sleep operation (<100A)
 Programmable data averaging
 Programmable slope, offset and format settings for each of the 8-channels
 Built in extended SDI-12 commands for setup and configuration.
 Plug-in terminal connectors

1.1 Description

The H-4280 is primarily used to interface simple analog sensors to a SDI-12 compliant data logger. Many
sensors such as potentiometers, thermistors, and pressure sensors can be connected directly to the H-4280.
Each channel can be configured with a y=mX+b linear equation to convert the input voltage into user units
such as temperature, pressure, feet or meters. The linear equation has a slope (m) term and an offset (b)
term. At the factory the slope is set to 1.00 and the offset to 0.00, with these values the measurement will
be in units of Volts. The linear equation will work for sensors such as potentiometers, shaft encoders and
4-20mA transducers with linear outputs. The y=mX+b equation will not work with thermocouples,
thermistors and other sensors having a non-linear response. For these sensors, leave the slope = 1.0, offset
= 0.0 and perform the more complex math operations in your data logger.

1.2 Input Settings

When the data logger issues an aM! command to initiate a measurement, the H-4280 makes 8­measurements, one for each channel. Each channel can be configured to make Unipolar/Bipolar and
Single/Differential measurements. The results of the 8-measurements are placed in the sensor buffer and
can be collected with aD0! and aD1! commands.

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Introduction 1-1

Unipolar 0 to 5.0 Volts (resolution is 1.2mV)
Bipolar: ±5.0 Volts (resolution is 2.4mV)
Single Ended: Measurement is referenced to ground
Differential: Measures the difference between two adjacent input channels (0-1, 2-3, 4-5, 6-7)

The H-4280 always makes 8-measurements, even if one or more of the channels is configured for a
differential measurement. For example; if Channel 0 is configured for a differential measurement, the
Channel 0 measurement is determined by the input voltage on both Channel 0 & 1. Subsequently a
measurement is made for Channel 1, with the results determined separately by the settings of Channel 1.
Normally if Channel 0 is configured for a differential measurement, the results of the adjacent channel
measurement (Channel 1) is ignored by the data logger (and vice versa).

1.3 Single-Ended Analog Inputs

A single-ended analog measurement is one which is referenced to ground. The H-4280 can make up to eight
single-ended measurements. Both unipolar and bipolar measurements can be selected. The 12-position
input connector has 3-terminals for making ground connections. Unused inputs may be left floating,
however the measurement data from unused inputs channels is undefined and will drift.

1.4 Differential Analog Inputs

A differential analog measurement is one which measures the difference between two input terminals. The
two terminals have positive and negative input response respectively. The H-4280 can make up to 4
differential measurements. Both unipolar and bipolar measurements can be selected. If the (+) input will
always more positive than the (-) input, set the channel to “unipolar”. The unipolar setting has the best
resolution. If the (+) can be less positive than the (-) input, set the channel to “bipolar”. The bipolar setting
allows the measurement to go negative but has the shortcoming of 1-bit less resolution.

1.5 Excitation Output

The H-4280 has a precision 5.00V excitation output terminal for powering potentiometers, thermistors and
other sensors. The +5Vref terminal is internally connected to the A/D converter. Measurements made with
resistance sensors powered from the +5Vref terminal will be “ratio metric” in that errors in the absolute
value of the reference cancel out. The +5Vref output is normally turned off to save power while the
module is in its sleep mode and is switched on before a measurement is made. The “warmup time” is a
programmable delay (1 to 999 seconds) which elapses before the first measurement is made. If desired, the
excitation output can be programmed to remain active while the module is asleep. The +5Vref terminal is
for powering potentiometers, thermistors and other low current senors. Do not draw more than 50mA from
the +5Vref terminal.

1.6 Sensors With Current Output

The H-4280 measures input voltage. Sensors which output current can be connected to the H-4280 with
the aid of a shunt resistor. For example, a 4-20mA sensor can be interfaced by connecting a precision 250
ohm shunt resistor between the input and a ground terminal. When the sensor is transmitting its 20mA
maximum output the H-4280 will input 5.0Volts: ( 5.0V = .020mA x 250 Ohms).

1-2 Introduction

H-4280

1.7 Averaging

The H-4280 can make up to 700 measurements/second (per 8-channels) The module makes multiple high
speed measurements, averages the results (simple mean) and reports one measurement per channel. The
number of samples can be programmed from 1 to 65535, the H-4280 comes from the factory configured to
make 100 samples for each channel (100 x (1/700)=0.142 seconds ). The number of samples per
measurement (1-65535) is the same for all 8-channels.

H-4280

Introduction 1-3

1-4 Introduction

H-4280

Installation And Setup

2.1 Installing The H-4280

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LOG® H-4280 is an 8-channel analog to digital SDI-12 “sensor”. Many sensors such as

potentiometers, thermistors, and pressure sensors can be connected directly to the H-4280

Chapter 2

2.2 General Installation Recommendations

The H-4280 housing and connectors are not weather tight. The H-4280 must be installed in a protected
location or a weather tight enclosure. The housing has a 4-terminal connector for making power and SDI­12 connections and a 2-segment, 12-terminal connector for connecting the analog inputs. The connectors
can be detached while making the connections.

Caution: Remove all power from the unit before making any connections.

Before beginning the installation take a minute to plan out your station grounding and wiring scheme. Use
a single point ground system design to avoid having high current (power) flowing into or out of the ground
terminals of the analog input connector. If your sensors have separate signal and power connections,
connect only the signal and its ground reference to the input connector. Use shielded cables where possible.
Use a shielded, twisted-pair cable when making connections to a differential input. Install lightening and
other transient voltage protection if the sensors and wiring are exposed to damage. Power the sensors from
the same battery or power supply which supplies the data logger, this makes certain input voltages to the
H-4280 are not present if the H-4280 is powered off.

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Installation And Maintenance 2-1

2.3 +5Vref Output

The H-4280 has a precision 5.00V excitation output terminal for powering potentiometers, thermistors and
other sensors. The +5Vref terminal is internally connected to the A/D converter. Measurements made with
resistance sensors powered from the +5Vref terminal will be “ratio metric” in that errors in the absolute
value of the reference cancel out. The +5Vref output is normally turned off to save power while the
module is in its sleep mode and is switched on before a measurement is made. The “warmup time” is a
programmable delay (1 to 999 seconds) which elapses before the first measurement is made If desired, the
excitation output can be programmed to remain active while the module is asleep. The +5Vref terminal is
for powering potentiometers, thermistors and other low current senors. Do not draw more than 50mA from
the +5Vref terminal.

The warmup delay is configured with the extended “aXRWT!” and “aXWWTnnn! commands. The
+5Vref power mode during sleep is configured with the extended “aXRPM!” and “aXWPMnn! commands.
See Chapter 3 for details.

2.4 Averaging

The H-4280 can make up to 700 measurements/second (per 8-channels) The module makes multiple high
speed measurements, averages the results and reports one measurement per channel. The number of
samples can be programmed from 1 to 65535, the H-4280 comes from the factory configured to make 100
samples for each channel (100 x (1/700)=0.142 seconds ). The number of samples per measurement (1-

65535) is the same for all 8-channels. This setting is configured with the extended “aXRMC!” and

“aXWMCnnn! commands. See Chapter 3 for details.

2.5 Channel Settings

Each channel can be configured to make Unipolar/Bipolar and Single/Differential measurements.

Unipolar 0 to 5.0 Volts (resolution is 1.2mV)
Bipolar: ±5.0 Volts (resolution is 2.4mV)
Single: Measurement is referenced to ground
Differential: Measures the difference between two adjacent input channels

These and other settings are configured with the extended “aXRCn!” and “aXWCn! commands. See
Chapter 3 for details.

2-2 Installation And Maintenance

H-4280

2.6 Slope & Offset

Each channel can be configured with a y=mX+b linear equation to convert the input voltage into user units
such as pressure, feet or meters. The linear equation has a slope (m) term and an offset (b) term. At the
factory the slope is set to 1.00 and the offset to 0.00, with these settings the measurement will be in units
of Volts. The linear equation will work for sensors such as potentiometers, position sensors and 4-20mA
transducers with linear outputs. The y=mX+b equation will not work with thermocouples, thermistors and
other sensors having a non-linear response. For these sensors, leave the slope = 1.0, offset = 0.0 and
perform the more complex math operations in your data logger. The slope and offset settings are
configured with the extended “aXROn!” & “aXWOn nn!”, “aXRSn!” & “aXWSn nn!” or the “aXRCn!”
& “aXWCn! commands. See Chapter 3 for details.

2.7 Data Format

The number of digits printed past the decimal point can be configured for each channel. For example if
Digits = 2 for a particular channel the respective data will have two digits beyond the decimal point (x.xx).
At the factory all 8-channels are set for 3-digits beyond the decimal point. These settings are configured
with the extended “aXRCn!” & “aXWCn! commands. See Chapter 3 for details.

2.8 Programming Your SDI-12 Data Recorder

You must prepare your data recorder to receive and record the H-4280 data. Since data recorders differ,
refer to your data recorder manufacturer's directions. In general, program the data recorder to input 8­values via the SDI-12 port. All eight parameters do not need to be actually recorded. Your data recorder
must issue an “aM!” command, then collect the data with “aD0!" and “aD1!" commands, as explained in
Chapter 3. Four parameters are returned in response to the “aD0!” command and four more with the
“aD1!” command.

The H-4280 places eight parameters in its data buffer:

a+A.AAA+BB.BBB+C.CCC+D.DDD+E.EEE+F.FFF+G.GGG+H.HHH<CR><LF>

Where: a = SDI-12 address 0-9, A-Z

A.AAA = Channel 0
B.BBB = Channel 1
C.CCC = Channel 2
D.DDD = Channel 3
E.EEE = Channel 4
F.FFF = Channel 5
G.GGG = Channel 6
H.HHH = Channel 7

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