Xylem H-3311 User Manual
OWNERS MANUAL
V2.1
H-3301/3311
INCREMENTAL SHAFT ENCODER WITH SDI-12 AND QUADRATURE OUTPUTS
D34 0514
CONTENTS & WARRANTY
This user manual is a guide for the H-3301/3311 shaft encoder. For more information, updated
manuals, brochures, technical notes, and supporting software on the H-3301/H-3311 shaft encoder
please refer to waterlog.com or contact your sales representative.
For additional assistance, please contact us at +1.435.753.2212 or sales@waterlog.com
WaterLOG® Warranty..................................................................1
Chapter 1: Introduction...............................................................2
Operation....................................................................................
Programming the Data Recorder.............................................
Programming the H-3301/3311...............................................
Installation...................................................................................
Making Output Connections....................................................
Words of Caution.......................................................................
Testing.........................................................................................
Chapter 2: H-3311 LCD Display................................................7
Overview.....................................................................................
Read Button Operation.............................................................
Using the Adjust Knob to Change Current Stage Value.......
Using the Adjust Knob to Change SDI-12 Address...............
Chapter 3: SDI-12 Command and Response Protocol.........9
Standard SDI-12 Commands..................................................
Extended SDI-12 Commands Unique to H-3301/3311.......
Measure Command..................................................................
Measure Command with CRC.................................................
Concurrent Measurement Command....................................
Concurrent Measurement Command with CRC...................
Send Data Command..............................................................
Continuous Measurements.....................................................
Continuous Measurements with CRC....................................
Send Acknowledge Command..............................................
Initiate Verify Command..........................................................
Send Identification Command................................................
Change Sensor Address..........................................................
Zero the Position Command...................................................
Read User Offset and Read User Slope Commands...........
Write User Offset and Write User Slope Commands..........
Test Display...............................................................................
Appendix A: Specifications.....................................................
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Contents & Warranty
“WATERLOG™ PRODUCTS MANUFACTURED BY YELLOW SPRINGS INSTRUMENTS CO., INC. are
warranted by Yellow Springs Instruments Co., Inc. (“YSI”) to be free from defects in materials and
workmanship under normal use and service for twelve (12) months from date of shipment unless
otherwise specified in the corresponding YSI pricelist or product manual.
WaterLOG™ products not manufactured, but that are re-sold by YSI, are warranted only to the
limits extended by the original manufacturer. Batteries, desiccant, and other consumables have
no warranty. YSI’s obligation under this warranty is limited to repairing or replacing (YSI’s option)
defective products,which shall be the sole and exclusive remedy under this warranty.
The customer shall assume all costs of removing, reinstalling, and shipping defective products to YSI.
YSI will return such products by surface carrier prepaid within the continental United States of America.
To all other locations, YSI will return such products best way CIP (Port of Entry) INCOTERM® 2010,
prepaid. This warranty shall not apply to any products which have been subjected to modification,
misuse, neglect, improper service, accidents of nature, or shipping damage. This warranty is in lieu
of all other warranties, expressed or implied. The warranty for installation services performed by YSI
such as programming to customer specifications, electrical connections to products manufactured by
YSI, and product specific training, is part of YSI’s product warranty. YSI EXPRESSLY DISCLAIMS AND
EXCLUDES ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE. YSI is not liable for any special, indirect, incidental, and/or consequential damages.”
A complete TERMS AND CONDITIONS OF SALE can be viewed at:
http://www.ysi.com/terms-and-conditions.php
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INTRODUCTION
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Introduction
The WaterLOG® H-3301/3311 is a digital shaft encoder which measures water depth by
monitoring the position of a float and pulley. The H-3311 has the same functionality as the H-3301
with the addition of a built-in display and manual offset adjustment feature making it easier to setup
and use in the field. See Chapter-2 for details concerning the LCD display and offset adjust control.
The H-3301/3311 is easy to use and works with any SDI-12 data recorder. For older loggers,
ALERT systems and the weather service LARK, the H-3301/3311 has a quadrature output that is
equivalent to the Handar 436A type shaft encoder. The “Serial-Digital Interface” is ideal for data
logging applications with the following requirements:
• Battery powered operation with minimal current drain
• Low system cost
• Multiple sensors on a simple three wire cable
• Up to 250 feet of cable between a sensor and the data recorder (Use of H-423, SDI-12 to RS485
converter extends the range to 1000’s of feet)
The H-3301/3311 has the following features:
• Scales the encoder position into user units of feet, meters, etc.
• Precision dual bearing design with special low temperature lubricant
• Threaded shaft compatible with older mechanical shaft encoders
• Zero backlash
• 200 counts per revolution for the SDI-12 output
• Sealed enclosure protects from moisture and dirt
• Low current operation (less than 2 milliamps)
• High speed encoder circuitry prevents missing counts due to rapid float movement from
wave action or sudden movement in freeze/thaw conditions - 15 ft/sec typical
• Water resistant connectors provide easy hookup
The LCD display on the H-3311 provides the following additional features:
• Continuous display readout always shows last measured value
• ‘Read’ button causes the H-3311 to continuously update the display while the button is pressed
• The adjust knob allows the user to manually set the stage
• The adjust knob allows the user to manually set the sensor SDI-12 address
Operation
The H-3301/3311 is a precision shaft encoder with a resolution of two hundred counts per revolution
(0.005 ft with a 1 ft circumference pulley). The H-3301/3311 has an internal microprocessor controlled
digital counter which monitors two digital outputs from a shaft position sensor. The sensor generates
quadrature pulses and phase information. The phase information indicates which direction the shaft
is turning. The H-3301/3311 continuously maintains a digital count representing the current position
of the shaft. The H-3301/3311 counts to ±32,768 steps.
During normal operation, the SDI-12 data recorder sends an address followed by a measurement
command to the H-3301/3311 sensor. The H-3301/3311 wakes up from its low power sleep mode,
converts the shaft position into Feet, Meters or other units programmed for the stage
measurement and stores this data in its data buffer. Once the data is ready, the data recorder
collects the data from the H-3301/3311’s data buffer.
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INTRODUCTION
Programming The Data Recorder
You must prepare your data recorder to receive and record the H-3301/3311 data. Since data
recorders differ widely, refer to your recorder manufacturer’s directions. The H-3301/3311
maintains two values or parameters about the shaft position: the Stage in the selected engineering
units and the Absolute Shaft Position in single unit steps. In general, program your data recorder
to record one or two values from the H-3301/3311 via the SDI-12 port. Usually only the first value
is recorded. The data recorder must issue an “aM!” command, then collect the data with a “aD0”
command, as explained in Chapter 3. The H-3301/3311 places two data values in its data buffer:
a±XX.XX±NNNN
Where:
a Is the the SDI-12 address 0-9, A-Z
XX.XX Is the current encoder position (Stage) in user units (Feet, Meters etc.)
NNNN Is the current absolute encoder position in units of steps (raw counts)
Programming The H-3301/3311
The H-3301/3311 comes from the factory with the following settings:
SDI Address: 0
Slope: 0.0050
Offset: 0.000
With these values Stage will be in units of feet when used with a pulley having a circumference
of 12 inches. The slope value can be changed to accommodate other pulley circumferences or to
change the data to other engineering units such as inches or Meters. The Address, Slope and
Offset setup is stored in EEPROM within the H-3301/3311 and will not be lost if the power is
disconnected. The extended commands for changing the slope, offset and sensor address are
described in detail in Chapter 3. If more than one sensor is to be connected to the SDI-12 bus,
make certain each sensor has a different sensor address.
Many applications use a shaft encoder to monitor water in a stilling well. A float and pulley
translate the water level to rotation of the encoder’s shaft. When the H-3301/3311 is installed,
the encoder will be at a position determined by the current water level. When the H-3301/3311 is
powered up it resets its internal position count to 0. All subsequent measurements will be
relative to this initial position. If a measurement in absolute units or stage is wanted, you will
need to change the OFFSET value to match the current stage as measured by a staff gauge or
other datum.
Incremental encoders such as a quadrature encoders, monitor CHANGES in shaft position. With
an incremental encoder, if the power is lost the encoder reference or zero position is also lost.
The position count is maintained in RAM (not EEPROM) within the H-3301/3311. Storing the
position in non-volatile (EEPROM) memory would not protect from power loss because encoder
position changes would be missed during the loss of power. The H-3301/3311 protects its
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Introduction
position count with a software flag or “signature”. If the power is removed momentarily the
H-3301/3311 will resume operation using the current position count. If the power is lost long
enough to destroy the signature, when the power is restored the H-3301/3311 resets the position
count to 0000. To intentionally reset the H-3301/3311’s position count, disconnect the power for
5 to 10 seconds.
A backup battery input is also provided to maintain shaft position during main power interruption
or loss. Any shaft movements while main power is lost will still be recognized and when main
power is restored the measured values will reflect the shaft changes while main power was lost.
Without the backup battery the value would start again at 0.00 plus the current offset value.
With the shaft pointing toward you, rotating the encoder shaft counter-clockwise produces an
increasing (positive) shaft position value. If this is backwards from your needs, either program
the slope with a negative value for SDI-12 applications, or exchange the two quadrature
connections to the shaft encoder for quadrature applications.
Installation
The H-3310/3311 is suitable for outdoor environments but must be installed in a protective
enclosure or gauge house. Normally, the housing is screwed or bolted to a shelf in the gauge
station with the pulley and tape protruding over the edge of the shelf above the water. Make
certain the housing is level and the pulley and tape do not rub on any obstructions.
Making Output Connections
The H-3301/3311 has both a SDI-12 and quadrature outputs. The H-3301/3311 is an SDI-12
V1.3 compliant sensor. It connects directly to any data recorder with SDI-12 capability. In addition,
the H-3301/3311 provides a raw quadrature output for use with other data recorders having a
quadrature input.
The power for the H-3301/3311 is supplied by the SDI-12 +12V input. Table 1 shows the proper
connections. Refer to the wiring diagram printed on the side of the H-3301/3311 for the connector
pinout.
Table 1 Cable Connections
Pin Wire Name
A
B
C
D
E
F
G
Red
Black
Green
Yellow
Orange
Brown
Blue
+12V DC
Ground
Ground
SDI-12 Data
Quadrature Phase A
Quadrature Phase B
Battery Backup
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INTRODUCTION
Words of Caution
• Make certain the encoder’s output does not go negative or more than +5.0 Volts
• Make certain the ground and power pins are connected to the encoder
• Keep the lead wires as short as possible
• Use shielded cables in noisy environments
Testing
After completing the installation, test the encoder by manually rotating the pulley. For the H-3311
press and hold the “Read” button to observe the display. Make certain the readout matches the
expected measurement. For the H-3301 make an SDI-12 measurement and check for the expected
measurement data.
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