Data Delivery Devices RFScada 2DI-4DO Long Range Spread Spectrum Bi-Directional Wireless Telemetry Unit User Manual

RFScada User Manual Version 1.7 Copyright ©2002 Data Delivery Devices LLC   Page - 21 – 120 NE DeBell Suite B Bartlesville OK 74006      Tel 918-335-3318      FAX 918-335-3328 
VSD / VFD Control. 
 
A variable speed drive may be controlled at a distance using the RFScada units. Depending on the type 
of drive, the speed may be raised or lowered and other features may be operated. The RFScada units 
provide automatic shutdown in the case of any system or communication failures. 
 
 
 
  

RFScada User Manual Version 1.7 Copyright ©2002 Data Delivery Devices LLC   Page - 22 – 120 NE DeBell Suite B Bartlesville OK 74006      Tel 918-335-3318      FAX 918-335-3328 
Access Control / Monitoring 
Here a pair of wireless RFScada units remotely protect, monitor and control access to a secure location 
up to 20 miles away. Alarms are activated whenever access is required or gained. The electrical lock may 
be controlled remotely as well as locally. Remote indication is supplied to show if the door...

RFScada User Manual Version 1.7 Copyright ©2002 Data Delivery Devices LLC   Page - 23 – 120 NE DeBell Suite B Bartlesville OK 74006      Tel 918-335-3318      FAX 918-335-3328 
Security / Environmental Systems 
From up to 20 miles, without interconnecting wires the RFScada units can control and continuously 
monitor environmental systems such as pumps, fountains, heaters and security devices. Alarms are 
activated to indicate any fault conditions, and battery backup provides full operation during power...

RFScada User Manual Version 1.7 Copyright ©2002 Data Delivery Devices LLC   Page - 24 – 120 NE DeBell Suite B Bartlesville OK 74006      Tel 918-335-3318      FAX 918-335-3328 
External Antennas. 
In some situations, due to distance, obstacles or other factors an external 
antenna may need to be installed on one or possibly both units. If in doubt two antennas 
may be ordered, then one returned for credit if not required. Two FCC approved Yagi 
type antennas (9 dB and 12 dB gain) are offered for...

RFScada User Manual Version 1.7 Copyright ©2002 Data Delivery Devices LLC   Page - 25 – 120 NE DeBell Suite B Bartlesville OK 74006      Tel 918-335-3318      FAX 918-335-3328   
FCC RF Exposure Warning 
In order to comply with the FCC RF exposure 
requirements the RFScada unit 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 unit is not classified as a 
portable device...

RFScada User Manual Version 1.7 Copyright ©2002 Data Delivery Devices LLC   Page - 26 – 120 NE DeBell Suite B Bartlesville OK 74006      Tel 918-335-3318      FAX 918-335-3328 
Sample Questions and Applications. 
 
900 MHz vs 2.4 GHz  
It seems that everywhere you look another ‘spread spectrum’ 2.4GHz devices comes 
out, including cordless phones, local wireless computer networks for homes and offices, 
video cameras, video links etc. Isn’t the very popular 2.4GHz frequency band the way to 
go, a quick...

RFScada User Manual Version 1.7 Copyright ©2002 Data Delivery Devices LLC   Page - 27 – 120 NE DeBell Suite B Bartlesville OK 74006      Tel 918-335-3318      FAX 918-335-3328 
the terrain, terrain surface, obstacles, the antenna used, proximity to similar devices etc. 
As a very general guideline in a typical, outdoor location where each RFScada unit may 
be visible from the other and using the internal antennas supplied with the standard 
product a range of at least two miles is to be expected, and...

RFScada User Manual Version 1.7 Copyright ©2002 Data Delivery Devices LLC   Page - 28 – 120 NE DeBell Suite B Bartlesville OK 74006      Tel 918-335-3318      FAX 918-335-3328 
completely ignored. If ‘correct and double verified’ data does not arrive at a receiver for 
about 2 seconds the unit will extinguish the ‘COMMS OK’ status LED and set the 
‘COMMS OK’ relay output to inactive, ie its normally open contacts will open. If ‘correct 
and double verified’ data does not arrive at a receiver for about 5...

RFScada User Manual Version 1.7 Copyright ©2002 Data Delivery Devices LLC   Page - 29 – 120 NE DeBell Suite B Bartlesville OK 74006      Tel 918-335-3318      FAX 918-335-3328 
 
AC Power Loss and Generator Operation 
Our remote unit is powered from a generator that automatically starts and runs for a 
couple of hours then stops for a few minutes. The remote unit is successfully monitoring 
the tank level, and continues to operate correctly when the generator is stopped, 
powered by its internal...

RFScada User Manual Version 1.7 Copyright ©2002 Data Delivery Devices LLC   Page - 30 – 120 NE DeBell Suite B Bartlesville OK 74006      Tel 918-335-3318      FAX 918-335-3328 
for our many visitors. We would also like to be alerted when the gate is operated so we 
may monitor activity. The gate installation companies we have contacted all have just 
one possible solution left for us - digging a trench for over a mile around the lake and 
across the beautifully landscaped grounds, then installing a cable...