Xylem H-3531 User Manual

Model

H-3531 F lashLite™

Owner's Manual

Version 1.9

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/

WATERLOG Warranty

1. NATURE OF THE PRODUCT

This agreement accompanies a pressure measuring 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 availab ility and use of the PRODUCT is extended to you , the US ER, solely on t he basis of the ter ms
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 cons idera tion f or the acces s to and use of the PRO DUCT extended to you by DESIGN ANALYSIS
and to protect the confidential and proprietary information of DESIGN ANALYSIS, USER agrees as
follows:

®

(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
(a) What is Covered

DESIGN ANALYSIS warrants that for a period of twelve months from the time of delivery 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
defect s in materials and workmanship for a period of ONE YEAR from the date of del ivery.

H-3531 User Agreement/WATERLOG Warranty W-1

®

(b) What USER Must Do

If the product fails to satisfy the above warranty, USER must notify DESIGN ANALYSIS in
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, DES IGN ANALYS IS

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.

W-2 User Agreement/WATERLOG Warranty H-3531

®

Table of Contents

User Agreement/WATERLOG Warranty.........................................®W-1

Chapter 1 Introduction

1.0 Introduction ............................................................. 1-1

1.1 Unpacking...............................................................1-2

1.2 Check The Model Number.................................................. 1-2

1.3 Testing the System........................................................1-3

Chapter 2 Installation

2.1 Installing the WATERLOG H-3531 FlashLite™..................................®2-1

2.2 Water Depth............................................................. 2-1

2.3 General Installation Recommended Steps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.4 Connecting Your Data Logger............................................... 2-4

2.4.1 SDI-12 Interface...................................................2-4

2.4.2 RS-232 Output....................................................2-4

2.4.3 Quadrature Output.................................................2-5

2.4.4 0-5 Volt Analog Output.............................................2-5

2.5 Industrial Mode...........................................................2-5

2.5.1 4-20mA Output(Industrial Mode Only).. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

2.5.2 RS-485 Interface(Industrial Mode Only).. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2.5.2.1 Modbus..................................................2-6

2.5.2.2 H-355 Control.............................................2-6

2.6 Wiring and Installation Precautions........................................... 2-7

2.7 Programming Your SDI-12 Data Recorder.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

2.7.1 Programming the SDI-12 Address..................................... 2-7

2.8 Programming the H-3531 FlashLite™ Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

2.8.1 Setting the Stage. .................................................2-8

2.8.2 0-5V Analog Output. ..............................................2-9

2.8.2.1 Programming the 0-5V Output Range. . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

2.8.3 4-20mA Output(Industrial Mode Only).. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

2.8.3.1 Programming the 4-20mA Output Range.. . . . . . . . . . . . . . . . . . . . . . 2-10

2.9 Testing.................................................................2-10

Chapter 3 Maintenance/Troubleshooting

3.1 Maintenance............................................................. 3-1

3.2 Precautions.............................................................. 3-1

3.3 Troubleshooting..........................................................3-1

Chapter 4 Simple Menu Interface

4.0 Simple Menu Interface..................................................... 4-1

4.1 Connecting to the H-3531 FlashLite™......................................... 4-1

4.2 General Operations........................................................4-2

4.3 Menu Options............................................................ 4-3

4.3.1 P - Sensor Mode Options............................................4-3

4.3.2 V - Sensor Output Options........................................... 4-3

4.3.3 B - H-355 Bubbler Options..........................................4-3

H-3531 Table of Contents T-1

Table of Contents

4.3.4 A - SDI-12 Address................................................ 4-3

4.3.5 S - Stage......................................................... 4-3

4.3.6 D - Digits........................................................ 4-4

4.3.7 O - Offset........................................................4-4

4.3.8 U - Units.........................................................4-4

4.3.9 L - Slope.........................................................4-4

4.3.10 C - Averaged Measurements........................................4-4

4.3.11 M - Measure..................................................... 4-5

4.3.12 H - H-355 Bubbler................................................4-5

4.3.13 X - Exit.........................................................4-5

4.4 Sensor Mode Options Menu. ................................................ 4-6

4.4.1 P - Power Mode...................................................4-6

4.4.2 F - Fast Mode..................................................... 4-7

4.4.3 N - NOAA Mode.................................................. 4-7

4.4.4 R - Measure Rate..................................................4-7

4.4.5 M - Modbus Settings............................................... 4-7

4.4.5.1 Modbus Settings Menu...................................... 4-7

4.4.5.2 A - Address...............................................4-7

4.4.5.3 B - Baud Rate............................................. 4-7

4.4.5.4 P - Parity................................................. 4-7

4.4.6 D - Reset to Defaults............................................... 4-7

4.5 Sensor Output Options Menu................................................. 4-8

4.5.1 0-5V Output Options............................................... 4-8

4.5.1.1 Slope....................................................4-8

4.5.1.2 V - 0-5v Output............................................4-8

4.5.1.3 H - Max Stage............................................. 4-8

4.5.1.4 L - Min Stage. ............................................ 4-9

4.5.2 4-20mA Output Options. ........................................... 4-9

4.5.2.1 Slope....................................................4-9

4.5.2.2 M - Max Stage. ........................................... 4-9

4.5.2.3 N - Min Stage............................................. 4-9

4.5.3 Quad Output......................................................4-9

4.5.4 U - Update Outputs. ..............................................4-10

4.6 H-355 Bubbler Setup Menu................................................ 4-10

4.6.1 Tank Pressure.................................................... 4-10

4.6.2 Line Pressure.................................................... 4-11

4.6.3 B - Bubble Rate.................................................. 4-11

4.6.4 P - Purge Pressure. ...............................................4-11

4.6.5 D - Purge Duration................................................4-11

4.6.6 A - Auto Purge...................................................4-11

4.6.7 T - Purge Threshold...............................................4-11

4.6.8 M - Manual Purge................................................ 4-12

4.6.9 U - Update All Values............................................. 4-12

T-2 Table of Contents H-3531

Table of Contents

Chapter 5 SDI-12 Command and Response Protocol

5.0 SDI-12 Command and Response Protocol...................................... 5-1

5.1 Measure Command........................................................ 5-2

5.2 Measure H-355 Gas Purge System............................................ 5-4

5.3 Concurrent Measurement Command. .........................................5-5

5.4 Send Data Command. .....................................................5-6

5.5 Continuous Measurements..................................................5-7

5.6 Send Acknowledge Command............................................... 5-7

5.7 Initiate Verify Command. .................................................. 5-8

5.8 Send Identification Command. ..............................................5-9

5.9 Change Sensor Address Command........................................... 5-10

Extended SDI-12 Commands:

5.10 Extended Set Current Stage Command.......................................5-11

5.11 Extended Read/Write Offset and Read/Write Slope.............................5-12

5.12 Extended Read/Write Stage Digits..........................................5-13

5.13 Extended Read/Write Quadrature Output Enable.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14

5.14 Extended Read/Write 0-5V Output Enable.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.15 Extended Read/Write 0-5V_Hi and Read/Write 0-5V_Lo........................ 5-16

5.16 Extended Read/Write 4-20mA_Hi and Read/Write 4-20mA_Lo...................5-17

5.17 Extended Read Power_Mode and Write Power_Mode.......................... 5-18

5.18 Extended Read Measure Rate and Write Measure Rate.......................... 5-19

5.19 Extended Read Mean_Count and Write Mean_Count...........................5-20

5.20 H-355 Bubbler Commands................................................5-22

5.20.1 H-355 Read/Write Bubbler Enable Command......................... 5-22

5.20.2 H-355 Read/Write Bubble Rate Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23

5.20.3 H-355 Read/Write Purge Pressure Command. . . . . . . . . . . . . . . . . . . . . . . . . . 5-24

5.20.4 H-355 Read/Write Purge Duration Command.. . ... . . .. . . ... . . .. . . ... . . 5-25

5.20.5 H-355 Read/Write Auto Purge Enable Command.. . . . . . . . . . . . . . . . . . . . . . 5-26

5.20.6 H-355 Read/Write Purge Threshold Command... . . . .. . . ... . . .. . . ... . . . 5-27

5.20.7 H-355 Initiate Purge Command.....................................5-28

5.21 Extended Read/Write Fast Mode Enable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29

5.22 Extended Read/Write NOAA Mode Enable.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30

5.23 Extended “XTEST”. .................................................... 5-31

5.24 Extended “XDEF”. ..................................................... 5-31

5.25 Extended “XCFG”. .....................................................5-29

H-3531 Table of Contents T-3

Table of Contents

Appendix A Specifications................................................... A-1

Appendix B Modbus Protocol

B.1 Modbus Interface.........................................................B-1

B.2 Modbus RTU Transmission.................................................B-1

B.3 Modbus Function codes....................................................B-1

B.4 Holding Registers.........................................................B-2

B.4.0 ID String(RO)....................................................B-2

B.4.1 Modbus Address(R/W).............................................B-2

B.4.2 Stage Units Select(R/W)............................................B-3

B.4.3 Reserved(R/W)...................................................B-3

B.4.4 Modbus Baud rate(R/W)............................................B-3

B.4.5 Parity(R/W)......................................................B-3

B.4.6 User Stage Offset(R/W). ...........................................B-3

B.4.7 User Stage Slope(R/W).............................................B-3

B.4.8 Stage(RO).......................................................B-4

B.4.9 Pressure(RO).....................................................B-4

B.4.10 Temperature(RO). ...............................................B-4

B.4.11 Battery Voltage(RO)..............................................B-4

T-4 Table of Contents H-3531

Chapter 1

Introduction

1.0 Introduction

The WATERLOG H-3531 FlashLite™ is a Highly accurate digital pressure transducer
specifically designed for water level monitoring. The H-3531 FlashLite™ directly measures sdry
gas pressure over a broad temperature range. The typical application of the H-3531 FlashLite™
is to be used with the H-355 Gas Purge System however, the H-3531 FlashLite™ is a easy to
setup pressure sensor that can be used in many other applications.

The H-3531 FlashLite™ has SDI-12, RS232, and Modbus “smart” digital interfaces together
with Quadrature, 0-5V analog and 4-20mA output options. The H-3531 FlashLite™ makes
multiple pressure measurements, averages the results and converts the measurement data into
units of PSI, Feet, Meters or other engineering units.

The H-3531 FlashLite™ is easy to use and works with any SDI-12 V1.3 compliant data recorder
with the exception of the SDI-12 CRC commands. The “Serial-Digital Interface” is ideal for data
logging applications.

The H-3531 FlashLite™ has the following features:

®

!Simple to install, use, and maintain (no on-site calibration required).
!Battery operation with minimal drain.(Less than 1 milliamp)
!Performs extremely accurate measurements of dry gas.
!Linear deviation is less than 0.02%
!Up to 250 feet of SDI-12 cable or up to 1000's of feet with the H-423(SDI-12 to RS485

converter).

!Resolution is 1 part in 1,000,000
!Accuracy over temperature range exceeds ±0.02 ft. of water.
!Enclosure is nonconductive and corrosion proof.
!Sensor has an atmospheric vent for compensation of barometric pressure changes.
!Extended SDI-12 commands for setting the Stage to the current water elevation.
!RS-485 Modbus RTU mode interface.(Industrial mode only)
!RS-485 H-355 Gas Purge System control.(Industrial mode only)
!Simple RS232 menu interface for quick setup time.(No external module required)
!Designed to output a 4-20 mA signal.(Industrial mode only)
!Designed to output a 0-5V signal.(No external module required)
!Designed to output a Quadrature signal.(No external module required)
!Designed to output a RS232 signal.(No external module required)

H-3531 Introduction 1-1

1.1 Unpacking

The following is a list of items you should have received:

!W ATERLOG H-3531 FlashLite™ pressure transducer

®

!Main interface cable
!RS232 communication cable.(optional)
!Owner's Manual

1.2 Check The Model Number

Before installing your new WATERLOG H-3531 FlashLite™, check the information on the label

®

of the sensor enclosure. Check the model number, the range, and the output type to be sure that
you have received the instrument you ordered. The label will look similar to the following:

H-3531

Model

FlashLite Pressure Sensor

S/N 1103
Range: 0-15 PSI (34.6' H20)
Output:: SDI-12, RS232, 0-5V, and

Quadrature

This example shows that the WATERLOG H-3531 FlashLite™ measures pressure within the
range from zero to 15-psi.

1-2 Introduction H-3531

®

1.3 Testing the System

Before installing the H-3531 FlashLite™, you may wish to test the system by connecting it to your
data recorder in the shop or lab (See section 2.4 Connecting the Data Recorder). Testing the H­3531 FlashLite™ in the shop or lab and observing the data recorder's readings will familiarize you
with the instrument in an environment where it is easy to work and you are near a telephone if
questions should arise.

The H-3531 FlashLite™ is shipped from the factory with the SDI-12 address set to zero. You will
be able to issue SDI-12 commands using "0" as the address after connecting it to your data
recorder. From the "talk" or "transparent" mode of your data recorder or using an optional H­4191 (RS-232 to SDI-12 interface) with a terminal emulator like Hyper Terminal or Procom etc..,
issue an identify command ("0I!") to verify communication and then a measure command ("0M!")
to verify proper measurement operation. When the measurement is complete, the transducer will
return a service request which is simply its SDI-12 address. Your support software may not echo
the service request to the screen. If not, just wait the allotted amount of time for the measurement
to complete (See section 5.1 for interpretation of the SDI-12 response to a measure command).
When the measurement has completed, issue a retrieve data command ("0D0!"). This should
return your data values.

If you are unable to establish communication with the H-3531 FlashLite™, refer to section 3.3
Trouble Shooting. When you have exhausted all possibilities in the trouble shooting section, feel
free to call one of our support personnel at [phone] for assistance.

H-3531 Introduction 1-3

Chapter 2

Installation

2.1 Installing the WATERLOG H-3531 FlashLite™

The WATERLOG H-3531 FlashLite™ is a digital pressure transducer specifically designed for
water level monitoring. The H-3531 FlashLite™ directly measures dry gas over a broad
temperature range. Before proceeding with the installation, please consider several site
preparation and maintenance issues:

®

®

2.2 Water Depth

The following chart shows the maximum pressure to which the H-3531 FlashLite™ is factory
calibrated. The sensor can survive temporary operation up to twice the maximum rated pressure
for you model’s range. However, any measurements made beyond the rated pressure will be
inaccurate. The H-3531 FlashLite™ will be damaged if it is subjected to twice the maximum
rated pressure.

Model Pressure Range Water Depth Range Accuracy
H-3531-15 0 to 15 psi 0 to 34.60 ft. +0.007 ft
H-3531-30 0 to 30 psi 0 to 69.20 ft. +0.014 ft.

* NOTE: Depth calculations are derived from the standard equation that one PSI is generated by
a column of water 27.680 inches deep at 39.4EF.

*

H-3531 Installation 2-1

2.3 General Installation Recommended Steps

1. Find a suitable location for the H-3531 FlashLite™. Care should be taken to place
it where it will not be jarred, crushed or dropped. Remember, the H-3531
FlashLite™ is a precision instrument. If mounted vertically, the sides of the
enclosure with connectors should not be facing up. The enclosure of the H-3531
FlashLite™ is designed to be water resistant but not water proof. If the H-3531
FlashLite™ is mounted vertically, the possibility of damage to the circuit boards
due to condensation, if moisture does penetrate the enclosure, is greatly reduced.

2. Connect the pressure line between the H-3531 FlashLite™ and the bubbler system.
This can be done using the H-350-Install kit, where all the required hardware is
provided. If you did not purchase the H-350-Install kit, you will need to procure the
parts from your local plumbing supplier. You will need a 1/8" NPT male tubing
fitting for the pressure input port. It is recommended that you use 1/8" copper
tubing. The proper ferrules must be used to insure there are no leaks. The male 1/8"
NPT fitting screws into the pressure input port of the H-3531 connector panel
shown in Figure 2-1. On the bubbler manifold, you will need a corresponding
tubing fitting. Generally, a 1/4" NPT female to 1/8" tubing fitting is called for. The
NPT threads of these fittings need a coat of Teflon tape or anaerobic thread dope.
This helps in preventing leaks.

We strongly recommend that you use a pressure relief valve on the pressure input. If you
purchase one, make sure that the pressure rating matches the pressure range of your H­3531 FlashLite™. The pressure input requires a 1/8" NPT Male fitting. You should be
careful not to over-tighten the connector when installing it.

Figure 2-1 Gas-Purge Stream Gauge Installation

2-2 Installation H-3531

Components of the H-350-Install kit:

• 6 feet of 1/8" copper tubing

• 1/8" Tubing to 1/8" Male NPT fitting

• 1/8" Tubing to 1/4" NPT female fitting

• 1/8" Street "T"

• 1/8" NPT Male Pressure-relief valve (Rated for the pressure range of your

H-3531 FlashLite™)

3. Connect the main interface cable to your battery and/or data logger using the
appropriate pins shown in the table on the following page. If you are using the
SDI-12 interface, also connect the SDI-12 data line to the appropriate terminal on
the data recorder(see Section 2.4.1 SDI-12 Interface).

4. Make the connection to your data recorder as explained in Section 2.4.

5. Now you are ready to field test your H-3531 FlashLite™.

H-3531 Installation 2-3

2.4 Connecting Your Data Logger

The H-3531 FlashLite™ has SDI-12, RS232 and Modbus “smart” digital interfaces together with
quadrature, 0-5V analog and 4-20mA output. The H-3531 FlashLite™ is a SDI-12 V1.3 compliant
sensor excluding the CRC commands. It connects directly to any data recorder with SDI-12
capability. The instrument housing has a 7 pin main interface connector and a 3 pin RS232
communication connector.

7-pin Circular Connector 3-pin Circular Connector

Pin Color Function Pin Color Function

1

Orange

2

Brown

3

Blue

4

Green

5

Black

6

Red

7

Yellow

2.4.1 SDI-12 Interface

The user must connect pins 5,6, and 7 to the data recorder or the user can power the H­3531 FlashLite™ separate of the data recorder and connect just the SDI-12 data line(pin

7).

2.4.2 RS-232 Output

When the user wakes up the H-3531 FlashLite™ with this port while in sleep mode the H­3531 FlashLite™ makes a new measurement and updates the outputs if enabled and then
prints out the measured stage and temperature value. If the user sends a carriage
return(CR) following the wake up then the H-3531 FlashLite™ simple menu interface is

Phase A/RS485+
Phase B/RS485­0-5V Out/4-20mA+
Analog Gnd/4-20mA­GND
+12V Power
SDI-12 Data

1

N/A

2

N/A

3

N/A

RS232(TxD)
RS232(RxD)
GND

2-4 Installation H-3531

initiated and the H-3531 FlashLite™ waits for a command from the menu for 3 minutes
and then times out.

2.4.3 Quadrature Output

Pins 1 and 2 of the main interface connector are for simulating a quadrature shaft encoder
output. The user can enable this option by sending the appropriate SDI-12 command or by
using the simple RS232 menu interface as explained in section 4.3.5/5.12. The quad
output uses signals Phase A and Phase B and is updated every new measurement. The user
can also put the H-3531 FlashLite™ in power mode 3, which is a continuous loop mode
that causes the H-3531 FlashLite™ to update the quadrature output at a user defined rate
which is the measure rate(see section 5.17).

2.4.4 0-5 Volt Analog Output

Pins 3 and 4 of the main interface connector are for outputting a 0-5V analog signal based
on the stage. This is also an option that the user must enable by sending the appropriate
SDI-12 command or by using the simple RS232 menu interface as explained in section

4.3.12/5.13. This output is also only updated following a new measurement. The user can

put the H-3531 FlashLite™ in power mode 3, which will update the 0-5V output based on
the measure rate.

2.5 Industrial Mode

When the user orders the H-3531 FlashLite™ the user must specify industrial mode if 4-20mA
output, Modbus/H-355 bubbler control is desired, otherwise the user must send the H-3531
FlashLite™ back to Design Analysis Associates to change to industrial mode.

2.5.1 4-20mA Output(Industrial Mode Only)

Current loop sensors output a current rather than a voltage. The 4-20mA output will drive
standard industrial telemetry and process control instrumentation. Since the signal to
noise margin of 4-20mA is not large, take care to protect the wiring from noise and
interference. The loop power supply must be sufficient to maintain 8.5 to 35V across the
H-3531 FlashLite™'s output wires, in addition to whatever voltage is needed to maintain
20mA across the loop receiver and interconnect wiring. The +12.0V SDI-12 power source
will work only if the resistance of your loop receiver and wiring is less than 150 ohms.

8.5V + (150ohms * 20mA) = 11.5V

The 4-20mA output is reverse diode protected. The H-3531 FlashLite™ is not loop
powered, continuous +12V instrument power must be supplied via the 7pin circular
connector.

!Make certain there is 8.5 to 35V across the 4-20mA output wires.
!Make certain the H-3531 FlashLite™ is receiving +12V power.
!Use shielded 4-20mA cables in noisy environments.

H-3531 Installation 2-5

2.5.2 RS-485 Interface(Industrial Mode Only)

2.5.2.1 Modbus

Modbus is an industry standard serial digital interface for interconnecting Programmable
Logic Controllers (PLCs), intelligent sensors and other devices. The H-3531 FlashLite™
is a Modbus slave and has a serial RS-485 port for connecting to a Modbus compatible
host device. See Appendix B for the Modbus register definitions. Continuous +12Volt
power must be supplied to the H-3531 FlashLite™.

To activate the Modbus interface, the user must issue an extended SDI-12
command/change the power mode to 4 using the simple RS-232 menu interface(see
chapter 4 and 5) and set Power_Mode=4. This setting causes the H-3531 FlashLite™ to
remain awake and monitor the RS-485 port for Modbus messages. This setting can be
made at the factory if requested.

2.5.2.2 H-355 Control

The H-355 Control interface allows the user to program the H-355 Gas Purge System to
meet the environment that it is installed in. This is also an option that the user must enable
by sending the appropriate SDI-12 command or by using the simple RS232 menu interface
as explained in chapter 4 and 5. Once enabled this feature makes setting up the H-3531
FlashLite™ with the H-355 Gas Purge System quick and easy. As shown in Figure 2.1 on
page 2-2.

2-6 Installation H-3531

2.6 Wiring and Installation Precautions

!The data recorder must be earth grounded.
!The H-3531 FlashLite™ requires that the water be at ground potential. Mother

Nature takes care of this for surface and ground water.

!Make certain the pressure port connection is tight
!Make certain the sintered bronze vent port is not painted or covered

2.7 Programming Your SDI-12 Data Recorder

You must prepare your data recorder to receive and record the H-3531 FlashLite™ data. Since
data recorders differ widely, refer to your recorder manufacturer's directions. In general, program
the data recorder to input four values via the SDI-12 port. Usually only one or two of the
parameters are actually recorded. Your data recorder must issue an “aM!” command, then collect
the data with a “aD0" command, as explained in chapter 5. The H-3531 FlashLite™ places four
parameters in its data buffer:

a+AA.AA+BB.BBBB+CC.C+DD.D<cr><lf>

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

AA.AA = Stage (feet, inches, meters etc.)
BB.BBBB = Pressure (PSI)
CC.C = Temperature (C)
DD.D = Input Supply Voltage (Volts)

2.7.1 Programming the SDI-12 Address

If more than one sensor is to be connected to the SDI-12 bus, make certain each sensor has
a different sensor address. The H-3531 FlashLite™ comes from the factory with its
address set to zero. The address can be edited using the RS-232 menu interface or using
the extended SDI-12 command. Refer to chapter 4 and 5.

2.8 Programming the H-3531 FlashLite™ Sensor

The H-3531 FlashLite™ comes from the factory with the following programmable settings:

SDI Address: 0

Slope: 2.3067 (feet of H 0)
Offset : 0.00
MeanCount: 8

Power_Mode: 0 = “Sleep”

0-5V_Hi: 34.6 (feet, 0-15psi)
0-5V_Lo: 0.0
4-20mA_Hi: 34.6 (feet, 0-15psi)
4-20mA_Lo: 0.0

2

H-3531 Installation 2-7

With these values the Stage will be in units of feet when used in clean water. The slope can be
changed to accommodate other engineering units such as inches or meters. The setups are stored
in EEPROM within the H-3531 FlashLite™ and will not be lost if the power is disconnected. The
extended commands for changing these setups are described in detail in Chapter 5 and most of
these settings can be changed using the simple RS232 menu, see Chapter 4.

MeanCount is the number of raw pressure measurements averaged together to make one
measurement sequence. This setting determines how long the sensor will take to make a
measurement. MeanCount can be changed as described in chapter 4 and 5.

2.8.1 Setting the Stage

Many applications use the pressure sensor to measure water level in a gauge or reservoir.
The sensor translates water pressure to water level. When the H-3531 FlashLite™ is first
installed, you will want to adjust the Offset such that the measurement data (Stage)
corresponds to the current water elevation or stage as determined with a staff gauge or
other datum.

One of the ways to do this is by using the RS232 simple menu interface ran from
Hyperterminal or similar terminal program. See chapter 4 Connecting to the H-3531
FlashLite™ section. Once you have established connection your screen will look similar

2-8 Installation H-3531

to the above screen image. When the user sets the stage the H-3531 FlashLite™ to make a
fresh measurement and automatically updates the Offset as needed to produce the desired
Stage. To set the stage using the RS-232 menu press ‘S’ for “S - Stage:” and enter in the
current stage value and then press enter. Then press the ‘M’ key for “M - Measure” and
verify that the set stage command did execute. You should see that the offset value has
changed. The other way to set the stage is to send the extended SDI-12 “Set Current
Stage” command. The “aXSCSdd.d!” command is discussed in more detail in chapter 5.

Example of a H-3531 FlashLite™ Extended "Set Current Stage" command:

Command Response Time Values Description
"aXSCS2.3!" "a0061<cr><lf>" 6sec 1 Set the Stage to 2.3

Subsequent Command Response Description
"aD0" a+12.80<cr><lf> The new Offset

2.8.2 0-5V Analog Output

The H-3531 FlashLite™ has a 12-bit digital-to-analog converter (DAC) and a precision
voltage reference. The Stage is scaled into a 12-bit value and loaded into the digital-to­analog converter. The 0-5V analog output is updated whenever a measurement is made. If
no measurements are made, the 0-5V analog output becomes “stale”. For industrial
applications where the H-3531 FlashLite™ is connected to a SCADA or PLC system
instead of a SDI-12 data logger, the H-3531 FlashLite™ can be programmed to
automatically make continuous measurements. To program the H-3531 FlashLite™ to
make continuous measurements, issue an extended SDI-12 command and set
Power_Mode=3 or use the RS-232 menu interface. See chapter 4 and 5 for details. This
setting can be made at the factory if requested.

Note: When the H-3531 FlashLite™ is first powered up and the 0-5V analog output is
enabled, the output voltage is set to 0 volts. It remains at 0 volts until the first
measurement sequence.

2.8.2.1 Programming the 0-5V Output Range

The H-3531 FlashLite™ scales the current Stage data to drive the 0-5V analog
output. The 0-5V_Hi and 0-5V_Lo settings control how the Stage data is processed.
The 0-5V_Lo should be set to the desired Stage corresponding to a 0.00 volt
output. The 0-5V_Hi should be set to the desired Stage corresponding to a 5.00 volt
output. See chapter 4 and 5 for details on programming these settings.

2.8.3 4-20mA Output(Industrial Mode Only)

The H-3531 FlashLite™ has a 12-bit digital-to-analog converter (DAC), precision voltage
reference and a 4-20mA current transmitter. The SDI-12 and 4-20mA sections are isolated
from each other with a high voltage digital opto-coupler. The Stage is scaled into a 12-bit

H-3531 Installation 2-9

value and loaded into the digital-to-analog converter to control the current transmitter. The
4-20mA output is updated whenever a measurement is made. If no measurements are
made, the 4-20mA output becomes “stale”. For industrial applications where the H-3531
FlashLite™ is connected to a SCADA or PLC system instead of a SDI-12 data logger, the
H-3531 FlashLite™ can be programmed to automatically make continuous measurements.
To program the H-3531 FlashLite™ to make continuous measurements, issue an extended
SDI-12 command and set or use the RS-232 menu interface. See chapter 4 and 5 for
details. This setting can be made at the factory if requested.

Note: When the H-3531 FlashLite™ is first powered up, the output current is set to

4.0mA. It remains at 4.0mA until the first measurement sequence. The digital-to-analog

converter is powered from the loop side of the opto-isolator. If the loop power is
disconnected or is applied after the SDI-12 side is powered up, the data in the digital-to­analog converter will be lost. When the loop power is restored, the 4-20mA output will be
at an unknown value. Once a fresh SDI-12 measurement is made, the digital-to-analog
converter is loaded with new valid data.

2.8.3.1 Programming the 4-20mA Output Range

The H-3531 FlashLite™ scales the current Stage data to drive the 4-20mA output.
The 4-20mA_Hi and 4-20mA_Lo settings control how the Stage data is processed.
The 4-20mA_Lo should be set to the desired Stage corresponding to a 4.00mA
output. The 4-20mA_Hi should be set to the desired Stage corresponding to a

20.00mA output. See chapter 4 and 5 for more details.

2.9 Testing

Before installing the H-3531 FlashLite™ in your field location, you may wish to first test the
sensor and data logger in your shop or lab. This allows you to become familiar with H-3531
FlashLite™ and the data logger in a controlled environment. The H-3531 FlashLite™ can be
tested with a pressure standard or water filled standpipe. However, for this test to work correctly,
the standpipe must be connected to the chassis ground of the data recorder. The wire establishes
a ground connection between the water and the data logger. Water and other conductive objects
isolated by a plastic bucket or table surface pick up AC noise from nearby lighting and power
lines. The AC noise is coupled by the water to the stainless diaphragm in the pressure sensor. If
a plastic or non-conductive tube is used to connect to the pressure source to the H-3531
FlashLite™, the sensor will be electrically isolated from the water media. The AC noise may
affect the pressure measurement due to large voltages between the water media and the sensor
(data logger) ground. This precaution is not necessary for field installations because surface water
and ground water are not isolated from earth ground.

2-10 Installation H-3531

Chapter 3

Maintenance/Troubleshooting

3.1 Maintenance

Sustained operation of the H-3531 FlashLite™ pressure sensor is almost maintenance free. As
with any precision instrument, the calibration should be checked on a regular basis. The
instrument has no filters or user serviceable internal parts.

3.2 Precautions

!Check for leaks, make certain the connections to the pressure port are tight.
!Make certain the atmospheric vent is not covered or blocked.
!Make certain the gauge station enclosure is open to the atmosphere. If the sensor is placed

in a cabinet or sealed enclosure, the cabinet must have a screened vent or other opening to
the atmosphere.

3.3 Troubleshooting

Experience over the years with pressure sensors has identified several common problems:

No SDI-12 response or intermittent data

1. Check all wiring including power and ground connections. Battery connections can
become corroded. Check for corrosion in the connectors and terminal strips.

2. The H-3531 FlashLite™ measures and reports it’s internal power supply voltage
along with Stage, Pressure and Temperature. Make a measurement and check to
see if the voltage is between 10.0 and 16.0 Volts.

3. Check the connections between your data recorder and the H-3531 FlashLite™
sensor. The power connections are made on the 7-pin circular connector.

4. Verify that there is not another SDI-12 sensor on the SDI-12 bus with the same
SDI-12 address as the H-3531 FlashLite™. Try communicating with the H-3531
FlashLite™ without any other SDI-12 devices on the bus. Sending a “*!” or “?!”
should cause the H-3531 FlashLite™ to return its own address as long as there are
no other SDI-12 devices on the SDI-12 bus.

Please feel free to call the factory for technical assistance and also with solutions you have found
to past problems.

H-3531 Maintenance 3-1