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offset by barrier

PostPosted: Thu Oct 11, 2012 5:04 pm
by Chris
The 2070 controller references offsets by barrier points rather than by phases. For example a typical 1234 (ring A) and 5678 (ring B) with 2 and 6 lagging and coord phases; would define its offset by the barrier between 2|3 and 6|7. I could fake the offet in by referencing begining of green of for 3 and 7 but I would be faking it in. You could give end of "barrier A" or end of "barrier B" as an option in the offset reference point.

Chris

Re: offset by barrier

PostPosted: Mon Oct 15, 2012 4:46 pm
by bullock
Thank you for the fine suggestion and enlightenment.

There's probably something subtle here that eludes me. I don't fully understand why it would be only faking it to use Start of Arterial Phase as the reference point (and checking the box "References Cross-Street Movement" as needed). If you change the phase sequence (swapping leading & lagging), that reference point still tracks whichever phase along the artery (or along the cross street) is the first to be served, so it seems like it's tracking the barrier.

Perhaps you would spell it out for me.

Regards.
Greg

Re: offset by barrier

PostPosted: Mon Oct 15, 2012 6:02 pm
by Chris
Well there is the situation where you switch the cross street sequence from lead-lead to lag-lag. You would have to adjust how your offset is referenced. Unfortunately defining the coord phase different from the offset has other issues.

Re: offset by barrier

PostPosted: Mon Oct 15, 2012 6:16 pm
by bullock
If the reference point is Start of Arterial Phase, then when you switch the cross street sequence from lead-lead to lag-lag, the reference point implicitly is the start of the through phases, which is still the barrier.

Re: offset by barrier

PostPosted: Fri Oct 19, 2012 8:25 pm
by Chris
I incorrectly assumed that the phase in paranthesis is what the offset is actual tied to. In reality the values in the parenthesis is simply telling me what phase this offset action is set to.