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Traffic Controller

The traffic controller is the piece of equipment that actually controls traffic signals and determines which phase will be given the green indication.  While there are many different models available, the instructions below are for the Traffic Control Technologies LMD 8000.  The instructions listed do not cover all of the LMD 8000's features, but are useful for the case studies presented on this web site.  

When inputting commands into the controller, you should use the NEMA phase numbering system as your reference.  That is how it is done in the field and it will make it easier for you to get help if you should need it.  So before programming the controller we should understand the NEMA phasing.  NEMA phasing is given below and is covered more in depth on the Background page.

Clear

This controller setting is used to clear all of the existing settings. This ensures that you are not "carrying someone else's baggage," so to speak.

Go to Main Menu (top left corner of screen) Press 3/Utilities Press 1/CLR Press 2/Clear Press 1/Controller Enter for all controller data to be cleared to default values or Press Prior Menu to Cancel Enter password (1111) if needed and then return to Main Menu Repeat Clear for all of the options (2-5)

Maximum Green

Maximum green time is the longest green time provided for a phase. You will need to use the maximum green, because this is where the actual green times of the signal timing plan will be entered. 

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 2/Phase Timing Press PGDN until MX1 appears and enter the time you have calculated (or were given) under the number corresponding to the NEMA numbers you have assigned to your phases. Note: You must press Enter or Arrow keys for changes to be saved.

Recalls

What this does is tell the controller to always "recall" to maximum green. In other words, you are programming the controller to always allocate the maximum green time to each of the phases.  Soft recall is used for actuated signals and will call the specified signal if there is not a call for any other signal.

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 1/Memory/Recall/CNA Set either Maximum Recalls (as in pretimed signals) or press PGDN to set Soft Recalls. Note: You must press Enter or Arrow Keys for changes to be saved.

Setting phases on

Using this controller setting we can set signal controller phases ON or OFF. 

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 3/Phasing/Sequence Turn the phases you are using ON and leave the rest OFF. Note: You must press Enter or Arrow Keys for changes to be saved.

Yellow

This command is used for changing yellow times. Unless you have calculated new yellow times, the default is a good value to use.

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 2/Phase Timing Press PGDN until YEL appears and enter the times under the proper phase. Note: You must press Enter or Arrow Keys for changes to be saved.

Red

The red time setting determines how much all-red time you have before the next green indication. Unless you have calculated all-red times, the default is good to use.

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 2/Phase Timing Press PGDN until RED appears and enter the times under the proper phase. Note: You must press Enter or Arrow Keys for changes to be saved.

Overlaps

This command sequence changes the order in which the controller calls up the phases. These steps will set up the signal for overlapped green phases.

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 3/Phasing/Sequencing Press PGDN and change the Phasing to "8. Lead/Lag". Press PGDN and select the phase pairs that you want reversed. Mark 1 for normal (numeric order) and 2 for reverse. Press PGDN twice and enter the phases you want to start with in each ring under INIT

Assign Detectors to Phases

This command lets the controller know which phase is called by each detector in actuated control. More than one detector can call a phase.

Go to Main Menu (top left corner of key pad) Press 2/Program - Read Mode Press 2/Controller Press 6/Detectors - Options Press 6/Detectors Press 1/Memory - Call - Extend In the "Call PH" row, set the phase that you want the detector (top row) to call. A phase can be assigned to more than one detector

Memory

This setting allows the controller to "remember" calls even if the detector is not activated. Memory is generally turned off in left and right turn lanes.

Go to Main Menu Press 2/Program - Read Mode Press 2/Controller Press 6/Detectors - Options Press 6/Detectors Press 1/Memory - Call - Extend In the "Memory" row, specify if you want the memory for each detector set on or off.

Dual Entry

This command will allow phases to act concurrently in actuated control, even if one does not have any calls on it.

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 6/Detectors - Options Press 3/Dual Ent - Cond Serv Under each phase number, enter the phase that you want to come up with it. For example, if you always want phase 4 and 8 to be together, enter 8 below the 4 and vice versa. Leave zeros for normal operation.

Changing Sequence

This command tells the controller to operate in dual ring mode, which is used for actuated control.

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 3/Phasing/Sequence Press PGDN and select 2. NEMA Dual Ring for the phasing sequence.

Passage Time

Passage time is the allowable gap between vehicles in actuated control.

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 2/Phase Timing In the PSG row, set the Passage Times to the proper value.

Minimum Green

Minimum green time is used in actuated signalized intersections. It is the initial interval that allows all vehicles potentially stored between the detector and the stop line to enter the intersection.

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 2/Phase Timing In the MGR row, set the Minimum Green times to the proper value.

Pedestrian Phasing

This setting determines how much time the pedestrian movements are allowed. If the these times are greater than the traffic phase times, the phase will stay green until the pedestrian signals time out. If you do not have pedestrians, be sure these values are set to ZERO!!

Go to Main Menu Press 2/Program/Read Mode Press 2/Controller Press 2/Phase Timing Press PGDN twice and enter the values for the WALK time (WLK) and the Pedestrian Clearance time (PCL). Note: You must press Enter or Arrow keys for changes to be saved.

Restart

Use this command to reinitialize the controller after changes have been made to ensure they are being implemented.

Go to Main Menu Press 3/Utilities Press 1/Restart Press 3/Restart

Run Status

Press the Run Status button This brings up the Run Status Menu, which shows the operations of the controller.  Ensure that your controller is properly operating before starting the simulation