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airGATEWAY 

 

  

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Application Note 

15  LIMITATIONS IN THE NUMBER OF DEVICES 

In its minimal extension, the “airLINK” network is composed of one Gateway and one Router or one End-
device. 

To determine the maximum network extension, that is the maximum number of nodes that can be used in 
the network, several factors must be taken into consideration: 

1) Device addressing space: internal Gateway constraints limit the maximum number of devices internally 
mapped to 112 (with addresses ranging from 16 to 127). 

2) Maximum Number of End-Devices: The maximum number of end-devices that can, at any one time, be 
'children' of a given Router (or Gateway) is 32. Practical questions of safety and redundancy recommend 
having at least two possible parent routers for each End-Device installed, and this leads to use of at least 
one router every 16 End-Devices. 

3) Practical reasons recommend never exceeding the limit of 60 Routers. 

 

16  NOTES ON THE RADIO COVERAGE OF THE DEVICES 

The radio coverage of the devices is approximately one hundred meters in the open field, that is, without 
the presence of any obstacles. In the closed field, the capacity is significantly reduced and highly variable, 
depending on the individual case. Often dividing walls or reinforced floors can prove to be insurmountable 
obstacles.  

It is not always possible to determine the best position for the devices, particularly the routers, according 
to theory; rather it must be determined empirically by trial during the actual installation. 

 

17  NOTES ON BUILDING A NETWORK OF DEVICES 

There are some practical rules for correct construction and installation of a network of “airLINK” devices. 

1) When possible install the Gateway in a central position respect to the other nodes. 

2) The Gateway must be able to communicate with at least two routers. 

3) Each router must be able to communicate with at least two other routers. 

4) Each router must not be able to communicate with more than sixteen other routers. 

5) The number of routers must be calculated according to the number of End- Devices. Arrange at least 
one router every 16 End-Devices. 

6) Each End-Device must be able to communicate with at least two routers. 

7) When possible install all devices in high positions and at a distance from metal masses. 

8) When possible install the devices so that they fall within eyesight. 

9) Limit the radio traffic as much as possible: experience has taught us that  it is advisable to never 
exceed an overall maximum number of messages every  three seconds. This limit thus becomes the 
minimum setting for the transmission frequency parameter for each node and this, in turn, depends on the 
number of nodes in the network. If “n” indicates the number of nodes in the network, we recommend that, 
for each node, the automatic transmission time must be set greater or equal than “3*n” seconds. 
 

 

Summary of Contents for airLINK

Page 1: ...Instructions for the creation of the network airLINK Application Note M98253901 03 14A...

Page 2: ......

Page 3: ...NING CLOSING AND ADDING NEW DEVICES 9 7 1 CREATING A NETWORK 9 7 2 OPENING A NETWORK 9 7 3 CLOSING A NETWORK 9 7 4 JOINING NEW DEVICES TO THE NETWORK 9 7 4 1 Joining end device type sensors actuators...

Page 4: ...airGATEWAY 4 o 13 Application Note...

Page 5: ...pability Usually battery powered b airLINK nodes linked to network with router functions Usually powered from mains airBRIDGE airREPEATER others but only one airGATEWAY The radio devices in these two...

Page 6: ...Valid Gateway addresses are ranging from 1 to 7 The default configuration is peripheral Nr 1 Address 1 1 2 3 4 Weight 1 2 4 Baud Rate ON Address 2 1 2 3 4 Weight 1 2 4 Baud Rate ON Address 6 1 2 3 4...

Page 7: ...work creation the Gateway stores the parameters describing the network in its non volatile memory so that when the Gateway is turned OFF subsequent operation is not compromised and when it is turned O...

Page 8: ...lly closed network which can only be opened from the airGATEWAY Network opening and closing operations are performed by pressing the push button on the airGATEWAY or by using the Modbus protocol to se...

Page 9: ...not lost and when it is turned on again it will resume functioning on the network it was previously joined to The process for join a device to the network differs depending on the type of sensor actu...

Page 10: ...y sends out the message containing the new parameter 12 BASIC NOTIONS ON THE MODBUS PROTOCOL The data stored in the Gateway can be read and modified using the Modbus RTU Remote Terminal Unit protocol...

Page 11: ...eating the network The R router type nodes are the basic constituents of the network they play an active role in maintaining and routing radio traffic from and to other devices in the network The prer...

Page 12: ...possible to determine the best position for the devices particularly the routers according to theory rather it must be determined empirically by trial during the actual installation 17 NOTES ON BUILDI...

Page 13: ...for the return The warranty is void if the equipment has been subject to misuse or the customer did not follow the instructions for storage installation and maintenance contained in this manual We und...

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