Data Delivery Devices VHF, UHF & ISM Wireless RTU RFScada 8ADI-9DO 4ADI-5DO User Manual

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 71 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
Radio Options 
  The two RFScada devices described in this manual may operate with many different wireless 
(and hard wired) communication options. The most popular units have low power ISM 902-928MHz 
spread spectrum radios installed, but these are not suitable for all applications. The following table 
summarizes current standard options; please note that the flexible ‘generic’ radio interface available 
on the RFScada board supports other radio frequency and power options not described here. Please 
consult with the factory for other possible radio installations, including operation with existing radios. 
 
Radio Option  Radio Location   Notes 
None  No radio  For direct PC connection or using a single shared radio between 
multiple connected RFScada boards.  
902-928MHz 
ISM Low Power RFScada board  Lowest RF cost, no license required, typically used with internal 
antenna. Range up to 25 miles line of sight.  
902-928MHz 
ISM High Power RFScada board  Low RF cost, better range than ISM low power, no license required. 
Range up to 40 miles line of sight. 
148-174MHz 
VHF 1, 2 Watt RFScada case  Low RF cost on 4ADI-5DO, medium on 8ADI-9DO. Much better 
range and non line of sight coverage than ISM, especially in rural, 
hilly environments. FCC license required. Largest antenna required 
for optimum performance.  
148-174MHz 
VHF 5 Watt RFScada case  Medium RF cost. Best range and non line of sight coverage in rural 
environments. FCC license required. Largest antenna required for 
optimum performance. 
450-490 MHz 
UHF 1, 2 Watt RFScada case  Low on 4ADI-5DO, medium on 8ADI-9DO RF cost. Much better 
range and non line of sight coverage than ISM, especially in urban, 
reflective (buildings etc.) environments. FCC license required. 
Medium size antenna required for optimum performance.  
450-490 MHz 
UHF 5 Watt RFScada case  Medium RF cost. Best range and non line of sight coverage in 
urban, reflective (buildings etc.) environments. FCC license 
required. Medium size antenna required for optimum performance. 
    
  All units in a network need to have the same type of radio option installed to be able to 
communicate correctly; so when selecting a radio system it is important to consider all locations that 
may eventually have to communicate in the network.  
 
Typical examples show RFScada 
devices with license free ISM modules 
and internal antennas  installed. On 
the left is the lower powered version, 
and the higher powered (SS1) version 
is on the right.  
 
Below shows RFScada 4ADI-
5DO and 8ADI-9DO units with 5 Watt 
radio transmitters installed. Note that 
the RFScada 4ADI-5DO main board 
provides power for the radio whereas 
the 8ADI-9DO device requires the 
separate power supply board and a 
larger case.  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 72 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
 
 
VHF / UHF Operating Frequency and Power Selection.   
Selecting the optimal frequency band has several implications when using the VHF and UHF 
radios. In most cases either frequency band will give excellent results; however license and antenna 
factors should also be evaluated when deciding which range to use as it can have significant affect on 
the complete system cost. For example, as a general rule UHF units require lower cost and physically 
smaller antennas than VHF units; if power outputs are limited to two watts the FCC license process 
may be quicker, more economical and easier to expand in the future. Many users feel that the best 
approach to radio selection is to simply choose the highest power available; but this is often not a 
sensible approach, especially if additional units may need to be added to the system in the future.  
The following two flow charts give an overview of the typical frequency and power selection process; 
note however that many other factors can influence the decisions and each system needs to be 
evaluated individually.   
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 73 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
Typical VHF / UHF Radio Band Selection  Flowchart 
 
 
 
 
 
VHF / UHF High 
Power Radios 
Required. 
Select Frequency 
Band, VHF or UHF
Required to 
communicate with 
existing system?  
 
YES 
NO
Existing VHF? 
 
Existing UHF?  Select VHF 
Select UHF 
Comparatively  short 
range / shallow hills? 
 
YES 
NO
Select UHF 
Select UHF 
Select UHF 
Line of sight ? 
 
YES 
NO
Predominately urban / 
buildings / reflective etc 
 
YES 
NO 
Select VHF  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 74 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
Typical VHF / UHF Radio Power Selection  & FCC License  
Application Process Flowchart 
 
VHF or UHF 
Frequency Band 
Already Selected 
Select Radio Power 
Output
Required to 
communicate with 
existing system?  
 
YES 
NO
Select power 
depending on 
existing system 
/ license 
Can system be fulfilled 
with 20 or less radios 
each 2 Watts or less ? 
 
YES 
NO
Determine GPS co-
ordinates of one central 
location. File license 
application  for 1 base & 
20 mobiles under a 
single FCC license 
5 Watt or higher power 
required ? 
 
YES 
NO
Determine GPS co-
ordinates of every single 
location (include every 
possible future location) 
Topology study / 
determine suitable 
location for ‘master’ unit 
 File application  for all 
locations for 5 Watt  
license(s) as required 
 File license application  
for all specified 
locations under a single 
FCC license if possible.  
Depending on the 
existing license a new 
application may or may 
not be required. 
 With frequency band decided, GPS co-
ordinates, requested power(s), 
bandwidth etc. file application with an 
FCC registered ‘Frequency 
Coordinator’  who will research and 
assign actual frequency. 
Frequency Coordinator files complete 
application with FCC.  FCC issues 10 
year license. Program radios to 
assigned frequency and install on site.  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 75 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
Advanced Radio and Network Diagnostics. 
For monitoring complex systems and troubleshooting individual radios an additional software 
tool, RFMonitor is available from Data Delivery Devices. This software program connects directly via 
the PC’s serial port to a radio module (not an RFScada unit) and allows the PC to monitor over the air 
radio traffic in real time. It can show transmitted data to and from all units which can be very useful on 
complicated systems. Typically VHF and UHF radios have antennas that may require tuning for the 
assigned frequency, this requires radios to transmit continuously for a few seconds while power levels 
are measured. The RFMonitor program may directly control transmission of the VHF and UHF radios, 
controlling transmission for limited times to allow the antennas to be correctly adjusted. The program 
also has a built in SWR calculator, 
and various ways to display raw 
data exchanged between 
RFScada devices. The RFMonitor 
program is not intended for end 
user use but rather system 
installers. To be able to monitor 
and display real time over the air 
data it does require a PC that is 
reasonably fast with XP or 
Windows 2000 installed. Contact 
Data Delivery Devices LLC for 
information on obtaining the 
RFMonitor program.   
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 76 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 77 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
External Antennas. 
In some situations, due to distance, obstacles or other factors an external antenna may need 
to be installed on one or more units. There are several sizes and styles available from Data Delivery 
Devices LLC, depending on the application. FCC approved Yagi type antennas and omni-directional 
models are offered for operation with the device.  
 
    
 
In order to comply with the FCC RF exposure 
requirements RFScada units may only be used with 
approved antennas that have been tested with it. A 
minimum separation distance of 20cm must be 
maintained from the antenna to any nearby persons. The 
RFScada units are not classified as portable devices per 
FCC Section 2.1093 
 
Typically an antenna cable ‘pigtail’ is used for the ISM radio options; it brings the signal from 
the radio module to a bulkhead female ‘N’ type feed thru. Here a surge arrestor may be directly 
installed if required, then the antenna cable connects to that. Depending on the model the surge 
arrestor may be mounted 
inside the cabinet if 
required; ensure that the 
surge arrestor case or 
block is securely 
grounded directly to the 
main input ground or 
ground rod. The surge 
arrestor has a field 
replaceable element, to 
access it remove the 
screw on the side of the 
arrestor.  
 
The total installed cost of ISM Yagi antennas including the 
cable, surge arrestor, pole (if needed), time and labor required 
etc. is usually in-significant between the larger and smaller 
antennas, so generally the higher gain antennas are 
recommended unless space prevents it. There is a better chance 
that a higher gain antenna will give satisfactory performance 
without requiring an external antenna on the other unit. 
 All of the antennas should be mounted with the short 
elements in the same direction, usually vertically. This 
discourages birds and other pests from remaining on the 
antennas, plus it helps to prevent heavy ice accumulation in 
extreme weather situations. The antennas should be aimed 
towards each other as shown below.  
 
CAUTION 
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 78 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
 
Several styles of antennas are available, including short Yagis, low 
profile antennas, omni-directional whip types etc.  
 
 The antenna signal 
dispersion patterns are 
shown. One (the E-
Plane) shows the 
radiation pattern as 
viewed from above; the 
other (H Plane) shows 
the pattern viewed from 
the side. 
Normal Orientation for Yagi Antennas  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 79 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
E plane  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
H plane 
             
  
  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 80 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990