Decatur Electronics SI-3C User manual

User’s Manual
Rev: 5-14-19
SI-3C™
System Interface 3
Compact Low Prole

Table of Contents
Welcome .............................................................6
About This Manual ....................................................7
1 Safety Information ....................................................7
2 Receiving Inspection ..................................................8
3 Getting Started .......................................................9
3.1 Introduction ......................................................9
3.2 Connecting The Serial Cable.......................................9
3.3 Optional Programming Cable ....................................10
3.4 Mounting Conguration .........................................10
4 Conguring the SI-3C™ ...............................................11
4.1 Equipment Needed ..............................................11
4.2 Setup............................................................11
4.3 Conguration Program Screen ...................................11
4.4 Conguration Items Screen ......................................15
4.4.1 Serial Number .................................................15
4.4.2 Unit ID ........................................................15
4.4.3 Measurement..................................................15
4.4.4 Target Report..................................................16
4.4.5 Target Select ..................................................17
4.4.6 Cosine Horizontal and Cosine Vertical ..........................17
4.4.7 Hold Time .....................................................18
4.4.8 Update Rate ...................................................18
4.4.9 Sensitivity .....................................................18
4.4.10 Baud Rate ....................................................20
4.4.11 Serial Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.5 Loading New Firmware & Conguring the SI-3C™ .................20
4.6 Congurtion Notes ..............................................23
4.7 SI-3C™ Command Set ............................................24
5 Performance Tips ....................................................28
5.1 How Radar Works ................................................28
5.2 Interference Sources .............................................28
5.2.1 Angular Interference (Cosine Eect) ............................28
5.2.2 Fan Interference ...............................................30
5.2.3 Electromagnetic Interference (EMI) .............................30

5.2.4 Feedback Interference .........................................30
5.2.5 Multi-Path Beam Cancellation ..................................30
5.2.6 Radio Frequency Interference (RFI) .............................30
5.2.7 Scanning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.2.8 Environmental Factors: Wind, Rain, Snow .......................31
6 Testing The Device ...................................................32
6.1 Tuning Fork Test .................................................32
7 Care, Cleaning, and Storage ..........................................33
8 Specications ........................................................33
8.1 Antenna Parameters .............................................33
8.2 Environment ....................................................33
8.3 Speed Range Parameters ........................................33
8.4 Power Consumption ............................................33
9 Legal Requirements ..................................................34
9.1 Documents .....................................................34
9.2 FCC Statement ..................................................35
9.3 Conditions ......................................................35
9.4 Installer Note....................................................35
9.5 End User Note...................................................35
9.6 Industry Canada .................................................35
10 Frequently Asked Questions (FAQ) ....................................36
11 Warranty.............................................................36
12 Service Return Procedure.............................................37
13 How To Order Additional Products ....................................38

SI-3C™User’s Manual
4
Welcome To Decatur Electronics, Inc.!
Thank you for choosing this Decatur Electronics product—the
System Interface 3 Compact (SI-3C)™, a highly advanced, low prole
directional radar unit that will reward your department with years of
dependable service. The SI-3C™ incorporates high performance and
long range with many leading features. We urge you to study this
manual before using the SI-3C™ so you can maximize the benets
of this sophisticated radar device. We believe you will be pleasantly
surprised by the features and advantages.
If you are as pleased with its performance as we think you will be,
ask your Decatur sales representative about other Decatur products
including the Genesis™ line of radars, the Onsite™ line of speed
trailers, dollies, pole signs and the Responder™ line of in-car video
systems.
Try any one of our products and see if you don't agree that it is the
best-in-class!
—The Management and Sta at Decatur Electronics

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5
About This Manual
This manual contains valuable information to help you set up, use
and maintain your radar so you can optimize its life and keep it at
peak performance. Please take a moment to read through it, and
keep it handy for future reference.
Note the following symbols in this manual:
Indicates a warning message about safety
precautions. Please read it carefully.
Indicates a helpful tip or precaution to note.
1. Safety Information
All service needs should be referred back to the manufacturer.
WARNINGS
• Do not over voltage the radar - it can damage the unit!
• The SI-3C™ is designed to operate o of conventional
+12 VDC (+9 VDC to +24 VDC) from the serial cable.
Important Warnings
• Disassembly of the SI-3C™ automatically voids any
warranty still in eect. There are no user serviceable
parts inside.
• Do not expose the SI-3C™ to excessive moisture. Never
submerge the device.
• Do not drop the SI-3C™ on hard surfaces since damage
could occur. Units damaged by dropping or abuse are
not covered for warranty repair.
Violation of these guidelines may void the warranty.

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2. Receiving Inspection
When you receive your SI-3C™:
• Inspect it for any freight damage that might have happened
during shipping or unloading. Take pictures to document any
damage.
• Notify the freight company immediately of any damage,
preferably while the driver is present.
• Record the damage on the bill of lading and keep a record of the
problems or damage.
• The package should include the following pictured items along
with this User’s Manual.
SI-3C™ Programming Software
S900-34
Tuning Fork
S769-78613-0
Serial cable

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3. Getting Started
3.1 Introduction
The SI-3C™ is a low prole radar specically designed to measure
speeds and export that speed information as RS232 data via the
special serial cable. This allows the SI-3C™ to be used for a wide
range of applications such as Radar Speed Trailers, trac speed
data collection (when used with the Decatur EZ Stat™ data logger)
or other uses where speed monitoring is desired. The SI-3C™ comes
with a Programming disk that allows the user to congure certain
parameters of the SI-3C™ for specic applications. Refer to Chapter 4
for conguration information. Additionally, a Radar Monitor program
is also available that allows you to display speed information on your
computer and record that information to a text le for analysis.
3.2 Connecting the Serial Cable
The SI-3C™ operates o of +12VDC and comes with a cable that
has two connectors. The circular connector plugs into the SI-3C™
and the DB-9 serial connector (shown in Figure 3.2) is used for
powering and communicating with the SI-3C. When connecting
the cable it is important to understand that unlike standard RS232
serial connectors that have no +12VDC provisions, the SI-3C's™ serial
connector has two pins dedicated to B+ and ground for the purpose
of powering the unit. Figure 3.2 shows the pin arrangement.
Figure 3.2
Front view SI-3™Serial Connector
Top Row Bottom Row
Pin 1 = +12VDC (power) Pin 6 = N/C
Pin 2 = RS232 TX Pin 7 = N/C
Pin 3 = RS232 RX Pin 8 = Remote On
Pin 4 = N/C Pin 9 = Ground (power)
Pin 5 = RS232 Ground

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3.3 Optional Programming Cable
For conguring and testing purposes a programming cable is
available. The cable is designed with two DB-9 connectors and
a black and red wire for supplying B+ and ground to the SI-3C™.
One end of the cable plugs into the serial port of a computer and
the other end into the SI-3C™. The same end that plugs into the
SI-3C™ has a red wire that is connected to +12 VDC and a black
wire that is connected to ground. A regulated power supply can
be used to supply the +12 VDC. Once the programming software
is installed on the computer then the SI-3C™ can be accessed and
parameters changed to meet your application. Refer to Chapter 4 for
programming information.
Figure 3.3
S769-127-0
Optional Programming Cable
3.4 Mounting Conguration
The SI-3C™ comes equipped with mounting holes. There are two
holes on each side of the mounting plate (See Figure 3.4). Use these
holes only to mount the SI-3C™ .
Figure 3.4
Mounting hole locations

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4. Conguring the SI-3C™
Before proceeding make sure your computer has Microsoft®Net
Framework Version 4.0™ installed. If not, you can install it by going to:
http://msdn.microsoft.com/en-us/netframework/aa569263.aspx.
4.1 Equipment Needed
• SI-3C™ radar device
• SI-3C™ Programming cable (S769-127-0)
• PC with either a usable RS232 serial port or a USB-to-RS232
adapter.
• RS232 cable to connect between the Power and
Communications adapter and the PC (if needed). This cable is a
9-pin RS232 cable with a male connector on one end and female
connector on the other.
• SI-3C™ conguration ash drive(S785-1-0)
• 12V power supply
4.2 Setup
1. Connect the SI-3C™ to the programming cable using the end of
the cable that has the red and black wire coming out of it.
2. Connect the red wire to the positive (+12 VDC) of the power
supply and connect the black wire to the negative (ground) side
of the power supply. Do not turn the power supply on.
3. Connect the other end of the programming cable to the serial
port of your computer. If you do not have a serial port and are
using a USB to Serial adapter make sure you have installed
the USB to serial adapter software (driver) rst. Then connect
the adapter to the programming cable. Plug the USB to serial
adapter into your computer's USB port.
4.3 Conguration Program Screen
1. Open and run the Congure4 (conguration) program; which is
shown in Figure 4.3a.

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Figure 4.3a
Conguration Program screen
2. The SI-3C™ Conguration Program is designed to automatically
recognize the assigned USB port. However, if for some reason
it does not recognize the port you can nd what port has
been assigned by checking "Device Manager/ Ports" on your
computer. The port assignment will appear as "USB Serial Port".
Note the port assignment. The example in Figure 4.3b shows that
Port 4 has been assigned. Your port assignment may be dierent
and the port assignment can change the next time the USB to
Serial adapter is plugged in to the computer.
Figure 4.3b
Device Manager screen

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3. From the Conguration Program/Com Serial Port Settings screen
(Figure 4.3c) click on the down arrow and select the COM port
that your PC has assigned. If you are connecting through the
computer's serial port, it will normally be "Com 1" or "Com 2".
If you are using the USB to Serial adapter, use the port shown
in Device Manager/Ports. Once the correct port is known, the
Device Manager/Computer Management screens can be closed.
Figure 4.3c
Comm port selection
4. Once the COM port has been selected, left click on the "Open
Port" button. A "COM port OPEN" message will be displayed
indicating that the COM port is now active. (See Figure 4.3d)
Figure 4.3d
Press the Open Port button
5. Press the CONFIGURE button. (Figure 4.3e)
Figure 4.3e
Press the CONFIGURE button

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6. Within 3 seconds of pressing the CONFIGURE button, apply
power to the SI-3C™ unit.
7. The Congure program will bring up the "SI-3C Conguration
Items" dialog box. (Figure 4.3f)
Figure 4.3f
Conguration Items screen
8. Select new options for programming as desired. An explanation
of the settings is described in Section 4.4.
9. Once new options have been selected, press the OK button. The
Congure program will upload the new settings and the SI-3C™
will start.

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13
4.4 Conguration Items Screen
The "SI-3C Conguration Items" screen allows for the setting of
several dierent parameters so that you can tailor the SI-3C™ to your
application. An explanation of each setting starting at the top of the
conguration screen follows:
4.4.1 Serial Number
Pre-Set at the factory.
4.4.2 Version & Unit ID
Pre-set at the factory.
4.4.3 Measurement
Select the speed format that the SI-3C™ is to use.
• Miles-per-hour - Select "mph"
• Kilometers-per-hour - Select "km/h"
• Meters-per-second - Select "m/s"
• Feet-per-second - Select "fps"
The maximum and minimum speed range for each of the speed
formats will be displayed in the "Max speed for this unit is:" and
the "Min speed for this unit is" windows. The speed ranges for the
various selections are:
• For"mph" the speed range is 1-330 mph (pre-set at 5-99)
• For "km/h" the speed range is 2-480 km/h (pre-set at 5-99)
• For "m/s" the speed range is 1-133 m/s (pre-set at 5-99)
• For "fps" the speed range is 1-440 fps (pre-set at 5-99)
As an example, Figure 4.4.3a shows the speed range when the
"mph" speed format is selected.
Figure 4.4.3a
Speed range for mph

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The speed range can be adjusted within those ranges by changing
the speed readings that appear in the "MAX Speed" and "MIN Speed"
windows (See Figure 4.4.3b). No vehicles will be reported outside
the minimum and maximum congured speeds
Figure 4.4.3b
Set the speed range you want to use
As an example, when "mph" is selected the minimum and
maximum speeds that can be processed are 1 to 301 mph
respectively. However, if the SI-3C™ is going to be used in an
application where any speed above 90 mph is to be ignored, then
the "MAX Speed" window can be changed to 90 and no speed
above 90 will then be processed. Likewise, if the SI-3C™ is to be
used where no speeds below 30 mph need to be considered then
setting the "MIN Speed" to 30 will cause the SI-3C™ to not report
any speeds below 30 mph.
4.4.4 Target Report
The "Target Report" has four selections and allows you to set the
direction reporting of the SI-3C™. It is recommended that the user
start with the "All" selection when rst setting up the SI-3C™.
All - Tracks the strongest overall target signal regardless of
direction.
• Approach and Recede - Tracks the strongest true directional
target coming towards or going away from the SI-3C™. This
mode contains directional ltering that will lter out any signal
that doesn't have a good directional signal.
• Approach - Tracks the strongest true directional target coming
towards the SI-3C™. This mode contains directional ltering
that will lter out any signal that does not have a good
directional signal.

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• Recede - Tracks the strongest true directional target going
away from the SI-3C™. This mode contains directional ltering
that will lter out any signal that does not have a good
directional signal.
Figure 4.4.4
Target Report
4.3.5 Target Select
Currently not selectable. A Target Select value of “Strong”is the
standard SI-3C™ conguration.
Figure 4.4.5
Target Select
4.4.6 Cosine Horizontal and Cosine Vertical
For bridge-type installations where the SI-3C™ is over the trac
and pointing slightly down, the vertical angle can be entered here
to ensure that the SI-3C™ calculates the correct vehicle speeds.
For installations where the SI-3C™ is at a signicant angle from the
road, the horizontal angle can also be congured. These two may
be used together. Keep the angles between 0 and 45 degrees for
maximum accuracy. Default is "0".
Figure 4.4.6
Cosine settings

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4.4.7 Hold Time
The "Hold Time" value indicates the length of time in milliseconds
the vehicle speed is displayed after the vehicle moves out of range.
The default "Hold Time" is 1000 milliseconds.
Figure 4.4.7
Hold Time
4.4.8 Update Rate
The selected speed format will be sent in whatever time interval (in
seconds) that you set. The "Update Rate"can be as low as 1 second.
or as high as 10 seconds. The "Update Rate"and the amount of
serial port activity do not aect the measurement accuracy of the
SI-3C™. The default rate is 1 Second.
Figure 4.4.8
Update Rate
4.4.9 Sensitivity
The SI-3C™ has a sensitivity range of 1-10 and is shipped with the
range setting at the (10) maximum (See Figure 4.4.9). The sensitivity
can be decreased for closer range if needed. When changing the
"Sensitivity" remember that if the setting is too low the SI-3C™ may
take too long to lock onto and display a speed and if too high it
may lock onto distant targets that are undesired.

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Typical ranges for an on-coming mid-sized sedan are:
Setting Range (feet)
1 350
2 575
3 800
4 950
5 1300
6 1700
7 1875
8 2400
9 2800
10 >3000
Figure 4.4.9
The distances will vary based on location, body of the car and
alignment of the antenna. It is normal for the range to vary by 10%
on identical cars.
Figure 4.4.9
Sensitivity Setting

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4.4.10 Baud Rate
The "Baud Rate" can be 1200, 2400, 4800, 9600, 19200, 38400,
57600, or 115200 bits per second. The SI-3C™ always uses 8 bits, no
parity, and one stop bit for its serial port conguration. The default
baud rate is 1200.
Figure 4.4.10
Baud Rate
4.4.11 Serial Protocol
Currently there is only one protocol available. <D> is a direction
character that is “+” for vehicles coming towards the sign, “-“ for
vehicles moving away, and “?”when the direction cannot be
determined. [S] represents the displayed speed. If a period is within
the square brackets it is the decimal point. Any zeros are sent as
described and do not change with a vehicle’s speed. The <cr>
signies the end of the outgoing message.
Figure 4.4.11
Serial Protocol
Once new options have been selected, press the OK button. The
Congure program will save the new settings into memory and
the SI-3C™ will start each time with these new settings until you
change them again.
4.5 Loading New Firmware & Conguring the SI-3C™
From time to time Decatur Electronics will release new rmware for
the SI-3C™. If you have received new rmware then save the rmware
to a le on your hard drive remembering the path to where the le is
saved. Connect the SI-3C™ to your computer as described in Section
4.2.

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1. Open and run the Cong 4 (conguration) program; which is
shown in Figure 4.5a.
Figure 4.5a
Conguration Program screen
2. The SI-3C™ Conguration Program is designed automatically
recognize the USB port. However, if it does not you can select the
port yourself. For instructions on determining the correct port
assignment refer to Section 4.3, point 2.
Figure 4.5b
Communications Port Selection
3. Once the correct port has been selected, Press "OPEN PORT".
Figure 4.5c
Press the Open Port button

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4. Choose SELECT UNIT from Menu.
Figure 4.5d
Press the Select Unit button
5. Choose "SI-3C" from drop down menu.
Figure 4.5e
Press the Select Unit button
6. The SI-3C Congure Items screen will appear. Select new options
as desired. Refer to Section 4.3, point 6 for additional information
on conguring items. Once changes have been made, or if no
changes are needed, press the "OK" button.
Figure 4.5f
Conguration Items screen