A Do-it-yourself Guide to Full- and Half-duplex RFid; Lessons ...

A Do-it-yourself Guide to Full- and Half-duplex RFid;
Lessons learned tracking bull trout in the upper Willamette
Vince Tranquilli
Fish Research and Monitoring Program

Objectives
• Know options available
• Describe two low-cost do-it-yourself
systems
• Why?
• Applications
• How to build antennas
• Resources available

Why do-it-yourself?
• Cost-effective
– 1 site vs. 10 sites ($3-5,000 vs $70-80,000)
• Not completely commercially available
• Site and project-specific requirements
• When it breaks you can fix it
• Get the information you want

3 System types
• Half-duplex
• Half and full-duplex
• Full-duplex

Which system should I use?
Application specific
• Marine, freshwater, estuary
• Large or small tributaries
• Tagging juveniles or adults
• Tagging 100’s or 100,000’s of fish
• Funding available
• Power options

Dam
Reservoir
South Fork
McKenzie
Adult escapement?
Frequency of repeat spawning?
Juvenile-to-adult survival?
Roaring
River

Dam
Reservoir
South Fork
McKenzie
Adult escapement?
Frequency of repeat spawning?
Juvenile-to-adult survival?
When do juveniles move downstream?
When are bull trout entrained?
Which route through the dam?
If recovered below dam do they survive?
What areas of the reservoir are they using?
When do fish leave the reservoir?
Roaring
River

Dam
Reservoir
Middle Fork
Willamette River
Where are fish spawning?
Iko Springs
Swift Creek
Indigo Springs
Chuckle Springs

Number of bull trout
100
75
50
25
0

Full-duplex Half-duplex
12 mm 23 mm
Image by Warren Leach

Number Number of of bull trout
trout
100
75
50
25
0

Scalpel blade to implant
Juveniles:
> 100 mm in length
body cavity
Sub-adult to Adult:
> 270 mm in length
dorsal sinus

Two Do-it-yourself Systems
• Zydlewski et al. 2001. J. Fish Biology
Stationary and mobile half-duplex system
• Bond et al. 2007. Transactions
Low-cost full and half-duplex system

TI-RFid System (half-duplex tags)
10 - 500’ twinax
Tuning board
Antenna
Power
Reader
Data logger

TI-RFid System (half-duplex tags)
10 - 500’ twinax
Antenna
12 – 18 VDC
0.75 Power - 1 Amp
Reader
Data logger

Scale

Low impact on fish behavior - Chinook salmon redd in antenna

Stream-width
1 loop antennas
< 30’ long
12 volt
12 gauge wire
Max. depth
~ 3.2 ft.

Stream-width
1 loop antennas
Larger antennas:
18 volt
< 30’ long
60’ x
12
3.2’
volt
80’ x
12
3’
gauge wire
190’ x 18”
Max. depth
~ 3.2 ft.

Stream Profile
Max. separation distance 1 m (depth)

Rock
Vector flow
Keep top and bottom wires parallel

Rock
Vector flow
Reduce antenna performance
Antenna still detecting fish
Keep top and bottom wires parallel

Materials
Avoid metal cable if possible, but if you use it you need metal fasteners every 6 inches
With rope you can use plastic twist ties

Building Antennas

4.9’
6’
10 -15’
1 antenna
2 loops
12 gauge
¾” space

1 antenna
2 loops
12 gauge
¾ inch space
9’ x 9’

Common Aggravation
No detection area - due to
metal interference in rebar
and antenna environment

Solution – Move away from metal or shield antenna

Swim-thru vs. Swim-over antennas
Map detection field in cross-sectional view
Tag and antenna orientation matter

Swim-over antenna
Manipulate the geometry to
improve performance
32”
6”

56”
48”
3 loops
8 gauge
1 – 1.5 m diameter
3 ¼” tube
Inductance 26 - 27.9 µH
1 – 1.5 m

Increase detection efficiency?
Increase detection depth?
Add a resonate
antenna

Increase detection efficiency?
Increase detection depth?
Add a resonate
antenna

Resonant Antenna
DO3

Resonant Antenna
DO3

Increase detection efficiency?
Cross stream multiple times
1 antenna
1 loop
12 gauge
3’ x 15’

Cross stream multiple times

1 antenna
2 loops
12 gauge
¾ inch space
5’ x 5’

Directional Movement

Downstream
A2 0:00:00
A1 0:00:01
Multiplex Antennas
A1 A2
Flow
Upstream
A1 0:00:00
A2 0:00:01

Fish Attractor Station
Fish attraction (light, bait,habitat)
Add video for untagged fish
1 antenna
8 gauge wire
Variable size, # of loops, spacing

Fish Attraction Station

How do I cover a larger area
and increase the depth?
1 antenna
1/O welding wire
2’ spacing
50’ x 6’
63.3 µH

2 Antennas
1/O welding wire
2’ spacing
50’ x 6’
63.3 µH

Number of bull trout
100
75
50
25
0

Two Do-it-yourself Systems
• Zydlewski et al. 2001. J. Fish Biology
Stationary and mobile half-duplex system
• Bond et al. 2007. Transactions
Low-cost full and half-duplex system

Allflex System
(full- and half-duplex tags)

Allflex System
(full- and half-duplex tags)

Allflex System
(full- and half-duplex tags)
1’
Reader
20’
Antenna
Power
Data logger
Must be rigid
Must stay submerged
Narrow tuning range
31 jumper settings
215 - 280 µH range

Allflex panel
reader board
$600 -1,000
2’ x 10’ Antenna
FDX 12 mm tag 15”
HDX 23 mm tag 19”
2’ x 20’ Antenna

Building FDX Antennas
2’ x 10’ Antenna
5 wraps
12 gauge THHN wire
No spacing between wires
2’ x 20’ Antenna
7 wraps

Building Antennas
Relatively cheap
Limiting factors
• Frame leaks no detection
• 2” flex and no detection

• What is the best system?
– Application specific
• Why do it yourself?
– Cost effective
– Fix it yourself
In Conclusion
– Build antennas to fit your needs
– Tools and resources available to help

Resources
• AFS - Bioengineering Section
online forum http://fishpass.org
• USGS - Manual compiled by Alex Haro
for half-duplex systems
• ODFW – Data logging software,
antenna designs, presentations
vince.tranquilli@state.or.us

Acknowledgements
• Gayle Zyldewski
•Alex Haro
• Warren Leach

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