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Elgal-Open-Field is a computerized irrigation control system, among the most advanced of its kind, for use in large open fields, farms, orchards, turf, public gardens and so on. Elgal-Open-Field has been developed by Eldar Shany Technologies, a company specializing in agricultural computerized control for a variety of applications.
The Elgal-Open-Field system is capable of performing irrigation, fertilization, filter flushing, water pumps activation, etc. precisely and automatically, from any distance, by using different communication methods such as direct lines, modem or wireless (RF) transmission.
System's Performances:
The following table describes the maximal ability of the software to handle various components. These are logical devices. Please refer to the hardware abilities as described in the controllers pages.
| Component |
Component type |
Logical items in software version
1.x |
Logical items in software version
2.x |
Plots
Irrigation valves
Irrigation programs
Irrigation Sequences
Irrigation heads
Water lines
Main valves
Water meters
Virtual water meters |
Virtual
Output
Virtual
Virtual
Virtual
Virtual
Output
Input
Virtual |
-
250.
2 per valve
100
20
-
20
100
20 |
100
200
200*
Program chains enabled
-
70
70
100
20 |
Fertilizer pumps
Fertilizer selectors
Fertilizer meters
Fertilization centers (Frtijets)
Main Fertilizer valves |
Output
Output
Input
Virtual
Output
|
20.
-
20
-
- |
30
20
30
10
10 |
Automatic flushed filters
Filtration groups |
Output
Virtual |
40.
10 |
40
5 |
Water supplying pumps.
Pumping stations |
Output
Virtual |
20
5 |
20
5 |
Drainage sampling points
Drainage counters
Condition input
Logic conditions
Various sensors (i.e. EC, pH, Wind, Radiation, Rain, Tensiometers, ET)
Various alarm outputs.
Outputs for general use (Diesel generators, etc.)
Counter inputs for general use
Operation time counters |
Output
Input
Input
Virtual
Sensors
Output
Output
Input
Virtual |
-
-
100
20
100
10
20
-
- |
10+main
10
100
30
100
10
20
30
30 |
Notice that:
⇒ Common application will only apply a small caption of the entire possible components. Many applications are likely to apply a large number of one type of components. Besides the hardware limitations, a consideration must take to CPU load. Please consult our technical department for any demanding application.
Principles and features:
| Issue |
Version 1.X |
Version 2.X |
Application orientation
 
|
Sequence orientation: Irrigation quantities set in the valve program. Valve programs combined in sequences where scheduling, conditions and co-valves are given. All water and fertilizer listed to the leading valve. |
Program orientation: The program is the heart of the application. Set participating valves (no "lead" and "co"), set a quantity, scheduling and conditions. Semi sequencing still possible by chains of programs. The irrigated and fertigated quantities divided proportionally between the participating valves according to own water meters or (more common) nominal flow rate. |
Water supply system
|
Irrigation "heads": Each valve must be engaged to one of 20 possible "Heads". The head is a logical group that doesn’t allow more then one engaged valve to irrigate at a time, unless it combined as a co-valve. |
Lines system: the water supply system organized in set of lines that connected accordingly and creates a net of water supply which is easy to visualize and manage. Downstream lines and valves are consuming water from the lines. Upstream lines and pumping stations (or wells) providing water to the lines. |
Fertigation
|
Valve engagement: Fertilizer injectors are freely called by the valves. Proportionally or fixed quantity fertigation set in the valve program. Each program can "call" for up to 3 injectors in parallel. |
Line engagement: Stand-alone injectors or fertigation centers are engaged to lines. An irrigation program may call for fertilizer from single injector, or for fertigation program from fertigation center. The system will check if the called fertigation injected somewhere in the water trail. Else it will invoke illegal fertigation. |
EC-pH control
|
Head: An EC-pH sensors kit engaged to an irrigation head. Constants and alarms set in the head. The required values for each irrigation are set in the valve’s program. |
Fertigation center: EC and pH control only available from within fertigation center. The engagement of the sensors and all alarms setting are in the fertigation center. Required values are set in fertigation programs. An irrigation program gains the required EC and pH values by calling a certain fertigation program in a certain fertigation center. |
A designated open-field hardware:
Remote Terminal Units
A. By cable (CRTU).
In a conventional method an electric wire is extended from each output or input to every unit in field. The CRTUs are installed along a single, 3-wired cable (maximum 128 outputs per cable), thus in big fields the total investment in cables is drastically reduced.
There are 2 basic models of RTUs
1. A large that unit includes 4 digital outputs for solenoid operation or a relay of latch type (12 VDC), 4 digital inputs (dry contact) and 2 analog inputs for alternate current 4-20 mA, or alternate voltage 0-10V.
2. A small unit that includes 2 digital outputs (12 VDC) and 2 digital inputs.
A 24 VDC voltage is supplied by the controller through the cable, so no batteries are needed.
Each unit has a lightning protection device for the whole cable.
Each unit is assigned a "private" code number using a Dipswitch.
A single cable can be extended to a distance of at least 5 km from the controller.
B. By radio (RRTUs)
These units are suitable when there is a long distance between the valves or pumps and the controller, or when the extension cables is not feasible due to different obstacles, such as rivers, roads, buildings, vegetation, etc.
The RRTU receives a radio signal from the controller and performs opening or closing of valves and pumps accordingly.
Each unit consists of the following components:
 |
A radio receiver, that can be adapted to frequencies approved for use in most countries. |
|
An interface card that includes 2 outputs for the operation of latch solenoids or latch relays (12 VDC). |
|
A lithium battery 3.6 VDC, which lasts under field conditions, up to 2-3 years. |
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Each unit is loaded with its own "private" code number, using a portable terminal. |
C.Wireless transmission unit for the RRTUs
Used to transmit data from the controller to the RRTUs, It includes the following elements:
A radio transceiver that can be purchased from different producers.
An encoder card between the controller and the transmitter.
A 12 V, 2.8 A/H rechargeable battery.
Multi or unidirectional antenna unit.
Antenna lightning protection.
Hermetically closed plastic casing.
The transmission and reception range under regular conditions, is up to 2 km.
D. Radio transceiver unit for communications to a PC
Used to transfer data from the controller to a central computer and vice-versa. Its main components are:
A radio transceiver.
A radio modem.
A 12 VDC power source.
An antenna unit.
Antenna lightning protection.
Hermetically closed box.
The effective transmission range, under regular conditions is, approximately 5 km. Several solutions can be obtained from the Eldar Shany Technologies's Engineering Department in order to increase this range.
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Open fields Irrigation Control
