Two-Wire Technology

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• Intro
• What Is Two-Wire?
  • Conventional Wire vs. Two-Wire
  • Advantages of Two-Wire
  • 5 Requirements for Two-Wire Specification
  • Types of Two-Wire Devices
• Decoders
  • Types of Decoders
  • Addressing a Multi-Zone Decoder
  • Retrofitting Powered Decoders
  • Consolidating Multiple Controllers
  • Decoder Addressing
  • Advantages of Smart Decoders
• Advantages of Two-Way Communication
  • Two-Way Communication to All Devices
  • Electrical Diagnosis
  • Real-Time Measurement of Soil Moisture
  • Real-Time Flow Data
  • Ability to Manage Complex Hydraulics
  • Optimization of Shared Water Sources
  • Stop, Start, Pause
• Summary

0:00 – 2:08: Intro

2:09 – 11:35: What Is Two-Wire?

Two-wire is just two wires.

Conventional Wire vs. Two-Wire (2:30)

A conventional wire system has a hot wire and a common wire running from each of the irrigation control valves back to the controller.

A two-wire system includes a two-wire path with decoder devices that interface with the control valves. It’s a much more streamlined configuration that allows the system to operate while reducing the amount of materials that are normally required for a conventional system.

Advantages of Two-Wire (3:16):

• Lower material cost – especially on larger systems
• Scalable – able to increase size by splicing into existing wire
• Easier to repair – Splicing two wires together rather than many
• Lower labor costs – less maintenance time saves labor hours
• Greener – less copper in the ground, lower impact
• Smarter than conventional wire

Photo examples of conventional system and two-wire system (5:00)

Another advantage of two-wire: Able to extend the wire length limits to support larger systems. This configuration allows for larger irrigation systems with fewer controllers. (5:45)

5 Requirements for Two-Wire Specification (6:50):

• Wire type: double-jacketed cable
• Wire connections: waterproof (DBR/Y-6 or equivalent)
• Wire length limits: varies by manufacturer
• Device limits: varies by manufacturer
• Surge protection: varies by manufacturer

Types of Two-Wire Devices (10:40):

• Smart sensors for conservation objectives
• Two-wire decoders for system operation
• Conventional wire retrofit capability
• Powerful flow management and monitoring

11:35 – 23:30: Decoders

Types of Decoders (11:35):

• Valve decoders
• Master valve decoders
• Pump start decoders
• Flow decoders
• Event decoders
• Soil moisture sensors

Addressing a Multi-Zone Decoder (12:17)

With multi-zone field decoders (2 & 4 zone), the label represents the wire closest to the common.

Retrofitting Powered Decoders (14:10)

Consolidating Multiple Controllers (15:30)

Illustration example of powered decoders (17:00)

Real-world example of a two-wire system with powered decoders: Summerlin HOA in Las Vegas, Nevada (17:30)

Question: Would it be cheaper to take out the old two-wire system to a new decoder rather than using the power bi-coder? Does it require the installation of new wire? (19:10)

Answer: No, it would not. The powered decoder in our example was simply installed. It didn’t require new wire.

Decoder Addressing (21:20)

“Addressing” is simply telling the controller which valve each wire is connected to.

Advantages of Smart Decoders (22:13)

• Any combination of two-wore or conventional wire
• Two-way advanced digital communication
• Simplified programming
• Devices are addressed from the controller
• Addresses can be changed from the controller
• LEDs on decoders to aid with diagnostics

23:31 – 33:20: Advantages of Two-Way Communication

Two-Way Communication to All Devices (23:31)

“Two-way communication” in this context means that a command can be sent from the controller to devices in the field to perform a function, but information can also be sent from the devices to the controller for diagnostic purposes or to make irrigation decisions.

Electrical Diagnosis (24:22)

Feedback from decoder devices reports the electrical health and functionality of components connected to them:

• Solenoid status
• Switch condition
• Sensor status

Real-Time Measurement of Soil Moisture (25:12)

• Makes better irrigation decisions, resulting in real conservation
• Every 10 minutes when system is idle, every 3 minutes when operating

Real-world example: Runtime schedule of a two-wire system in Utah. Installation of this system resulted on 38% water savings! (26:25)

Real-Time Flow Data (28:05)

Flow values read every 30 seconds and displayed during operation. The controller uses the flow values to monitor variances of learned flow and manage concurrent operation of zones based on the design GPM.

Ability to Manage Complex Hydraulics (28:53)

Optimization of Shared Water Sources (30:00)

Stop, Start, Pause (30:48)

Stop, Start, Pause a program when:

• A switch changes to closed or open
  • Even decoder
• A moisture reading is above or below a limit
  • Soil moisture sensor
• A temperature reading is above or below a limit
  • Air temperature sensor

Example of Stop, Start, Pause (32:08)

33:21 – end: Summary

• Two-wire technology simplifies the design, installation, and maintenance of irrigation systems.
• System performance is enhanced by the capabilities of two-wire.
• Smart decoders provide critical feedback to the controller to make better irrigation decisions and perform diagnostics.
• Two-wire enables the functionality to handle complex hydraulics and water sources.
• Allows integration of other site components that operate as a switch.

Question: Is there a break-even number of zones that make a two-wire system more economical than a conventional system? (35:20)

Answer: That depends on the current cost of copper, which can fluctuate quite a bit. It also depends on the cost of the decoders used in the system. With Baseline systems, two-wire generally becomes more economical with 40 zones or more.

Question: Are there any flow sensors or master valves that are not compatible with Baseline? (36:32)

Answer: Baseline’s flow decoders can read the pulse output from any flow sensor. Baseline-branded flow sensors are sourced from creative sensor technologies and are two-wire-ready – and therefore plug-and-play. The same goes for the hydrometers that Baseline sources from Netafim. Bottom line: Baseline can interface with any existing flow sensor or other brands’ flow sensors (except Hunter’s flow click) as long as they provide a pulse output.

Question: Is it true that Hunter has a proprietary output on their flow clicks? (38:25)

Answer: Yes, that is true. Therefore, Baseline is unable to interface with Hunter flow clicks.