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 - 51 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
Option Boards. 
Options are available from Data Delivery Devices LLC to add additional functionality to the 
RFScada system. These boards plug into a connector and are secured to standoffs already mounted 
on the lower half of the main board. Some option boards may be stacked for maximum flexibility. 
  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 52 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
Analog Output Options, AO2, AO4 & AO8 
 
Since many applications do not require analog outputs standard RFScada units do not have 
any 4-20mA outputs installed. Options (AO2, AO4 and AO8) are available to add 2, 4 or 8 analog 
output channels which may be installed at the factory or in the field. The following chart shows the 
connections, not all of the components may be installed depending on the version of analog output 
board. 
 
Connection Option Board Signal 
Analog Board J1-01  AO2, AO4 & AO8  Analog Channel 1 4-20ma Output  
Analog Board J1-02  AO2, AO4 & AO8  Analog Channel 1 Ground  
Analog Board J1-03  AO2, AO4 & AO8  Analog Channel 2 4-20ma Output  
Analog Board J1-04  AO2, AO4 & AO8  Analog Channel 2 Ground  
Analog Board J4-01  AO4 & AO8  Analog Channel 3 4-20ma Output  
Analog Board J4-02  AO4 & AO8  Analog Channel 3 Ground  
Analog Board J4-03  AO4 & AO8  Analog Channel 4 4-20ma Output  
Analog Board J4-04  AO4 & AO8  Analog Channel 4 Ground  
Analog Board J2-01  AO8  Analog Channel 5 4-20ma Output  
Analog Board J2-02  AO8  Analog Channel 5 Ground  
Analog Board J2-03  AO8  Analog Channel 6 4-20ma Output  
Analog Board J2-04  AO8  Analog Channel 6 Ground  
Analog Board J5-01  AO8  Analog Channel 7 4-20ma Output  
Analog Board J5-02  AO8  Analog Channel 7 Ground  
Analog Board J5-03  AO8  Analog Channel 8 4-20ma Output  
Analog Board J5-04  AO8  Analog Channel 8 Ground  
 
 
 
 
To install the analog output option in the field proceed as follows: 
First remove AC and DC power to the unit. 
Analog 1 Ground Analog 1 Output 
Analog 2 Ground Analog 2 Output 
Ground    Output 
Analog 3 
Ground    Output 
Analog 4  Ground    Output 
Analog 7 
Ground    Output 
Analog 6 Ground    Output 
Analog 5 
Ground    Output 
Analog 8 
Analog Board J2  Analog Board J1  Analog Board J5  Analog Board J4 
Analog Output Option Board (AO8 Shown)  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 53 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
 
 
 
 
 
Possibly lethal line voltages will be present on the unit’s 
circuit board when connected to AC line power. Before 
attempting to gain access, test or modify connections 
refer to a Qualified Person for assistance, instructions on 
safe operation and to ensure that connections meet all 
applicable safety procedures, standards and codes. 
 
Then open the unit and ensure there are not any wires obstructing access to the option board 
area. Remove the analog output option board from is packaging being careful to observe static 
damage warnings. Locate the output option board above the connector and standoff mounts, then 
carefully place it in position. It should fit snugly but with little resistance, if obstruction is felt ensure 
that all the connector pins are straight, lined up and mating correctly with the socket on the main 
board. Once it is snugly fitted use the six stainless steel screws supplied with the option board to 
secure the assembly. Connect any 4-20mA output signals as required. Close the unit door and restore 
power. There are no software changes required to use the analog output options, but ensure the 
system configuration is set to route the correct signals to the output options. 
 
The analog output signals are not isolated from ground, and the returned 4-20mA signal 
connects to ground at the option board. An external power supply for the analog outputs is not 
required, and must not be connected to the analog outputs to prevent possible damage to the 
RFScada device or external components. If an electrically isolated output is required then an 
external isolator must be used. The RFScada analog outputs will safely drive any loop resistance, 
including a short circuit, but if the load resistance is too high the correct output current cannot be 
maintained. The source voltage of the driver circuit is approximately 18 Volts DC when operating on 
AC line power, so the loop resistance should be less than 800 Ohms. Each output is electrically 
protected from transients so may safely drive long cable lengths that may be subject to transient 
pickup.  
Always try to ensure that the analog output signal current is returned to the analog output 
option board via the analog output connector and not via the system safety ground, since although the 
analog output option will still transmit the correct current it is possible, especially with multiple 
channels, to cause external earth leakage trips to occur in protective devices.    
DANGER 
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 54 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
 
4-20mA Current Loop  4-20mA Signal 
Amplifier on Output 
Option Board 
NOTE 
Try to ensure 4-20mA 
current returns via 
loop and not through 
the system ground   
This point may 
or may not be 
grounded 
depending on 
the device. 
External device with 4-
20 mA input such as 
signal amplifier, PLC, 
PC with analog input, 
display gauge etc. 
RFScada 
4-20mA Current Loop 
4-20mA Current Loop  4-20mA Signal 
Amplifier on Output 
Option Board 
RFScada 
4-20mA Current Loop 
4-20mA Signal 
Isolato
r
Output signals 
completely 
electrically 
isolated from 
RFScada
Typical 4-20mA Analog Output Connection 
Isolated 4-20mA Analog  Output Connection  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 55 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
Generic LMR / RS-232 / RS-485 Interface Board 
 
There are some applications where the standard spread spectrum radios installed on 
RFScada devices are not authorized for operation, or they are not the most suitable radios for 
particular distances and terrains. Instead of the standard factory installed spread spectrum radio a 
RadInt Land Mobile Radio board may be ordered for factory installation, this provides an additional 
generic interface (both RS-232 and RS-485) to allow operation with many different brands of radios. 
Note that the interfaces provided by the RadInt board are completely separate from and in addition to 
the standard RFScada RS-232 and RS-485 interfaces. The RadInt board may also be used for direct 
connection between RFScada boards using the additional RS-485 interface; this may be useful when 
many RFScada boards are located close together in local control applications and remote control is 
via the other serial port to one unit.  
The RadInt board has many programmable settings for interfacing with different radios, and 
also supports multiple baud rates, adjustable radio key up, radio key down, cycle time settings etc.  
      
 
 
There are other radio specific settings that may need to be set, depending on the brand and model of 
radio used a separate radio configuration program may be required to store the correct configuration 
settings, such as the radios over the air baud rate, frequency of operation, modulation type etc. Many 
of the settings may be viewed by looking at the ‘about’ menu from the RFScada configuration 
program; consult with the factory for help with changing these settings. Note that the PC control and 
configuration software needs to be Version 2.1 or later to access the LMR radio features.  The 
RFScada 1 Watt, 2 Watt, 5 Watt VHF and 1 Watt, 2 Watt, 5 Watt UHF radio options all utilize the 
RadInt interface.  
  Please consult with the factory for further information about various other radio options; as 
most of the newer radios may be interfaced.  
RS-232 LMR 
connection 
RS-485 LMR 
connection  Install jumper for 
RS-485operation  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 56 – 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 - 57 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
Spectrum Analyzer Mode and Network Integrity. 
 
  The RFScada units have extensive checksum and error detection for all exchanged data; any 
corrupted data is completely ignored by the system. If corrupted data continues to arrive without a 
good data packet for longer than the programmed ‘timeout’ value units will revert to a default state 
(unless the ‘comm fail override’ mode is enabled). As explained earlier the radio network state may be 
continually monitored from all units. For systems with many distributed units, in areas of heavy radio 
interference or many obstacles blocking reception an indication of relative signal integrity can be very 
useful. It allows identification of units in the network that may have a damaged antenna, require an 
additional directional antenna or perhaps need relocation.  
  The RFScada master unit keeps a continual log of data integrity, and when connected to a PC 
running the configuration and programming software the user may display a live spectrum analyzer 
display of data exchanged between all units. Operation is very straightforward, once the main 
program is running and connected to the master unit select ‘Network Signal Strength’ from the menu. 
Note that the connection must be to the master unit, as it is the only unit that has logged information 
on all data exchanged between units in the system.  
  A screen similar to the following will be displayed: 
 
 
 
 
 
  The 31 vertical columns represent the 31 possible slave units that may be in a system, unused 
ID’s will have a vertical value of zero. The scale may be zoomed in by adjusting the zoom slider, and 
the accumulated packet counts being used for the analysis may be reset by selecting the ‘reset  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 58 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
counts’ button. This is useful if a change has been made and the effects may be quickly observed. 
Note that larger samples give more accurate results. Moving the mouse pointer over each column will 
display the unit number and signal integrity as a percentage. In the example shown above there are 
31 slave units in the network, and all but two have good signal integrity above 90%. Unit 7, showing 
an integrity of 67.9%, is located in another building some distance away with the antenna removed. 
Unit 22, with an integrity of 29.4% is in a remote location and has a directional Yagi antenna installed, 
but the antenna is aimed away from the master unit so nearly all of its signal is miss-directed. It is 
obvious from the spectrum analyzer where there is room for improvement in this system; but as will be 
shown it is still possible to operate the RFScada system with heavy interference and signal loss.   
  The signal integrity is defined as the number of good, verified packets received from a slave 
unit divided by the number of packets transmitted to the slave. In a perfect environment this value 
should be 100%, if every packet transmitted had a perfect response. In reality radio signals are 
subject to a constant barrage of interference, including random radio energy in the atmosphere, 
interfering devices such as cellular phones, microwave ovens, motor controls, vehicle engine controls, 
radio energy emitted from electrical discharges such as lightning many miles away etc. For this 
reason the RFScada units do not revert to a default state as soon as one corrupted packet arrives; 
rather they keep trying to communicate and maintain the current output values until another good 
packet is exchanged or the programmable timeout expires.  
  By ensuring that the signal integrity is as good as may be reasonably expected under the 
circumstances and by selecting timeout values that are not too short, the statistically calculated time 
between any single ‘network error’ will typically be in hundreds or thousands of years. The following 
graphs give an indication of the expected time between a single network error, where units would 
change to a default setting for a complete network scan time (0.2 seconds to 6.5 seconds with ISM 
spread spectrum radios, and depending on the number of units in the network).  
 
Average Time between a Single Network Error vs Packet Integrity (1 Day Scale)
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.91
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time in D ays
Packet Integrity
1 Sec timeout2 Sec timeout5 Sec timeout10 Sec timeout20 Sec timeout
  
  The graphs are identical, with identical data, but with ‘zoomed in’ time scales to see detail in 
the curves. They show time on the X axis as 1 day, 1 year and 100 years. Note that five data curves 
are shown, corresponding to timeout settings of 1, 2, 5, 10 and 20 seconds (the RFScada default  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 59 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
setting is 10 seconds). As may be seen from the graphs, the timeout setting has a great influence on 
the packet integrity required to maintain reliable operation.  
 
Average Time between a Single Network Error vs Packet Integrity (1 Year Scale)
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.91
0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300 315 330 345 360
Time in D ays
Packet Integrity
1 Sec timeout2 Sec timeout5 Sec timeout10 Sec timeout20 Sec timeout
 
Average Time between a Single Network Error vs Packet Integrity (100 Year Scale)
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.91
0 3650 7300 10950 14600 18250 21900 25550 29200 32850 36500
Time in D ays
Packet Integrity
1 Sec timeout2 Sec timeout5 Sec timeout10 Sec timeout20 Sec timeout
 
  
  As an example we will assume the packet integrity is 80%. If the timeout is set at one second 
the system will probably generate a network error within a few minutes; for two seconds probably 
about 30 days, 5 seconds approximately once every 1,890,410,959 years. The RFScada default value  
						

							RFScada 8ADI-9DO/4ADI-5DO Manual Ver 3.6 Copyright ©2005 Data Delivery Devices LLC Page - 60 – Bartlesville OK Tel 918-335-3318      FAX 918-398-9990 
of 10 seconds allows ample tolerance for reliable communications; even with a signal integrity value 
of 37% an error would only be expected once every 68 years. Extending the timeout to 20 seconds 
lowers the signal integrity required to approximately 20% for a similar time between errors. The 
timeout will probably never need to be changed unless the application has exceptional circumstances.  
  In most circumstances, over a long time period external radio interference will increase, 
buildings will appear, trees will grow, traffic will become more dense etc., so although the default 
settings may appear to be extremely conservative it is recommended that the timeout not be reduced 
from the default values unless absolutely necessary.