controlling arrow board

I am trying to wire a roof mounted traffic control arrow light bar which can sequentially flash 6 leds to the left or to the right.

The arrows are turned on by appplying constant power to either the black wire for left arrow OR constant power to the white wire for right arrow.  If you apply power to both wires, nothing will happen. (not sure if it would fry controller) 

The switch panel I would like to use either has two independent constant switches or two independent momentary switches.  There is no option for DPDT switch ON-OFF-ON which is what I normally use.

How can I wire this up so that when you press the button for the left arrow it turns on, then if you press the buitton for the right arrow, it will turn on and turn off the power to the left arrow.  To shut off the arrows all together, I would think pressing the arrow button that is on again to turn it off?

Thanks,

- Chris

Chris Turrisi

Are you working with SPST switches? Are you saying you want to use the two momentary switches only?Kevin Pierson

It would be a lot of relays, but it could be done with (2) of these arrays. One for each direction. #86 on the far right relay is neg trigger = OFF. Regardless of which state the array is in, a (-) pulse turns the array OFF. Connect this terminal to the opposite button Lt Grn wire. This will turn off the opposite array (if it's on) when the button is pushed. Use a diode in each of these 4 wires to isolate the arrays from each other. Bands toward the button. A pilot light on the output (30 on far left relay) would help avoid confusion as to whether an array is off or on.

Thank you for the answers.  I will clarify some of the questions. 

I am planning on using a Wired HDH flat switch panel which allows SPST constant or momentary action. 

http://www.shopwiredhdh.com/Flat-Switch-Panel-AND-Relay-assembly-KIT-build-a-kit_p_451.html

Thanks,

Chris Turrisi