IP LOGGED:

[Viewed 9073 times]

SITE URL 01: www.VoltsAmps.com
SITE URL 02: www.SVBxLABS.com
SITE URL 03: www.HERF.tk

"This site is powered by viagra."

.:: Opticom ::.

Purpose:

The purpose of this project is to acquire an optocom signal from either an EMS or fire truck (FT) vehicle.


Materials:

I will be using a TI-89, CBL2, custom TI89 software, light probe, motor vehicle and other tools to help me.


Definitions:

Opticom - Device used in traffic control systems which allows emergency vehicle to control signal lights via combination of strobe pulses.
TI-89 - 89 Model of the Texas Instrument Graphing calculator
CBL2 - Computer Based Lab expansion for the TI graphing calculators.
EMS - Emergency paramedic vehicle
FT - Fire truck
FD - Fire Department
Light Probe - Device that attaches to the CBL2 and senses light intesity


Plan:

I will drive around looking for EMS or FT with opticom on near their stations, aim my light probe, and record at ~2kHz for 4 or 5 seconds. I will later have to filter out the other sirens from the data which shouldn't be too hard since the opticom is noticeably higher frequency. After having this data I will attempt to modify a flashlight to replay this exact pulse.


Attempt 1 (6/20/01):

I didn't have much success in locating an "active" EMS/FT but I made up a strategic plan. When I hear the fire siren go off (other than monday at 7:00pm when the FD has practice) I will head down to the fire house and wait for the trucks to return. They usually turn all their sirens on when they back into the garage. I'm not sure if they will leave the opticom on but it's worth a try.


Attempt 2 (6/21/01):

I was thinking to myself, since the opticom receiver has such a long and narrow visor, what is the closest distance to it that you can be for it to "see" the light pulses. I was thinking about this and came up with a formula. It may be wrong because I just made it at 4:54am so I hope you understand. Here is the formula...

Dmin = (L * (Hs - Ht)) / Vdia

Where:

Dmin = minimum horizontal distance to the sensor
L = length of the opticom visor
Vdia = Visor diameter
Hs = Sensor height from the ground
Ht = Transmitter height from the ground
The way I got this formula if from a few trig setups... tan(arctan(Vdia / L)) = (Hs - Ht) / Dmin

Then I just solved for Dmin. Please feel free to correct my algebra or my approach.


Data:

Sample 3M opticom log file from an intersection. ID is the vehicle identification number (most 3M systems accept 000). Minute is the minute of the day that the system was used. DOW is the day of the week, 0 being sunday. Number is the direction, 1 is rail premption, 2 is north, 3 is south, 4 is east, 5 is west. Type is the vehicle type. Status is what the vehicle requested.

[ID] [RECDATE] [RECMINUTE] [DATE] [MINUTE] [DOW] [NUMBER] [TYPE] [STATUS]
980 9/5/1997 1000 8/28/1997 229 5 5 Fire CYC PRMT
980 9/5/1997 1000 8/28/1997 230 5 1 Rail CYC PRMT
980 9/5/1997 1000 8/28/1997 230 5 5 Fire CYC PRMT
980 9/5/1997 1000 8/28/1997 231 5 0 Fire END
980 9/5/1997 1000 8/28/1997 232 5 5 Fire CYC PRMT
980 9/5/1997 1000 8/28/1997 232 5 0 Fire END
980 9/5/1997 1000 8/28/1997 233 5 5 Fire FLSH PRMT
980 9/5/1997 1000 8/28/1997 238 5 0 Fire END
1 10/4/1997 1084 9/29/1997 865 2 0 LP TOD FLSH
1 10/4/1997 1084 9/29/1997 866 2 0 LP END
1 10/4/1997 1084 9/29/1997 866 2 0 LP TOD FLSH
1 10/4/1997 1084 9/29/1997 866 2 0 LP END
1 10/4/1997 1084 9/29/1997 866 2 0 LP TOD FLSH
1 10/4/1997 1084 9/29/1997 867 2 0 LP END
1 10/4/1997 1084 9/29/1997 869 2 0 LP TOD FLSH
1 10/4/1997 1084 9/29/1997 869 2 0 LP END
887 10/4/1997 1084 10/4/1997 955 7 0 LP TOD FLSH
887 10/4/1997 1084 10/4/1997 955 7 1 Rail ALRED FLSH
887 10/4/1997 1084 10/4/1997 956 7 0 LP END
900 10/7/1997 1030 10/7/1997 1320 3 0 Fire TOD FLSH
900 10/7/1997 1030 10/7/1997 664 3 0 Fire END
900 10/7/1997 1030 10/7/1997 1320 3 0 Fire TOD FLSH
900 10/7/1997 1030 10/7/1997 672 3 0 Fire END
900 10/7/1997 1030 10/7/1997 1320 3 0 Fire TOD FLSH
900 10/7/1997 1030 10/7/1997 674 3 0 Fire END
900 10/7/1997 1030 10/7/1997 1325 3 0 Fire TOD FLSH
900 10/7/1997 1030 10/7/1997 698 3 0 Fire END
901 10/7/1997 1030 10/7/1997 1341 3 0 Fire TOD FLSH
900 10/8/1997 954 10/8/1997 952 4 0 Fire TOD FLSH
900 10/8/1997 954 10/8/1997 952 4 0 Fire END
900 10/8/1997 954 10/8/1997 952 4 0 Fire TOD FLSH
900 10/8/1997 954 10/8/1997 953 4 0 Fire END
900 10/8/1997 957 10/8/1997 1320 4 0 Fire TOD FLSH
900 10/8/1997 957 10/8/1997 300 4 0 Fire END
900 10/8/1997 966 10/8/1997 308 4 0 Fire TOD FLSH
0 ######## 619 ######## 1082 6 1 Rail ALRED FLSH
0 ######## 619 ######## 1091 6 1 Rail ALRED FLSH
0 ######## 619 ######## 680 2 1 Rail ALRED FLSH
0 ######## 619 ######## 682 2 1 Rail ALRED FLSH
299 ######## 619 ######## 708 2 1 Rail ALRED FLSH
299 ######## 619 ######## 710 2 1 Rail ALRED FLSH
299 ######## 562 ######## 979 5 1 Rail ALRED FLSH
701 3/21/1998 660 1/22/1998 591 5 1 Rail ALRED FLSH



Conclusion (6/17/02):

A visitor on my website had sent me an email recently which stated that he had worked as a firefighter/EMT for 13 years. He was also curious about the opticom frequency and had placed a solar panel connected to a frequency counted against the surface of the activated opticom. The readout showed 8Hz as the base frequency. I had also seen and read about devices that opperate on a base frequency of 14Hz. I am still wondering if the duty cycle of the light is important. Now it is time to modify a flashlight and use an LED flasher IC to pulse the light at 8Hz.

Here is a device I built and tested (unfortunatly it was sloppy and the frequency wasn't adjustable). It wasn't able to trigger any opticom sensors.


Here is my BS2SX setup that I will digitally program for exactly 8Hz and 14Hz pulses. The device will have an adjustable duty cycle and pulse frequency. It will power a flash light. At 8Hz a flash light bulb will be ok, but at 14Hz the filiment will not be able to cool down enough in time. I will consider using super bright LEDs or a laser pointer.




This is a 3M Opticom sensor.


Here is a website where they sell handheld opticoms but only to gov officials. They specify that 10Hz is for low priority and 14Hz is for high priority. The problem seems to be that the signal that is sent isn't just a base frequency. It is modulated. So back to plan A where I must either video tape a fire truck's opticom or get my CBL2 data logger and attach a light probe to it.

Images:


This is the Excelsor 12 Engine Co. fire house located near Rt. 304.


This is a Rt. 304 intersection. You can see it has 2 opticom sensors mounted in both directions.


This is an "up-close" shot of a sensor on Rt. 304.


This is a blue siren that flashes when the opticom sensor is triggered.


This I think is the opticom sensor on Rt. 59 because there is nothing else that looks like a sensor. There has to be an opticom sensor here because there are blue sirens.


This is one of the blue sirens on Rt. 59.


This is the strobe light on the EMS vehicle that produces light pulses that trigger the opticom sensor.


This is a FT with an opticom on the top left corner. It is high up because of the narrow and long light visor on the opticom sensor. But, the sensor can be triggered from the ground at larger distances

Copyright Rostislav Persion 2004