Coordination Modes   (MM->2->1)

          Coordination Modes         ->   
 Test OpMode  0       Force-Off FIXED
 Correction SHORT/LONG
 Maximum MAX_INH      FlshMode  VOLT-MON
 

NTCIP 2.5.4 COORD FORCE MODE PARAMETERS  provides 3 modes of coordination:

  1. FIXED Force Offs

  2. Floating (FLOAT) Force Offs

  3. OTHER - select one of the following Force-off+ modes from the right menu    

 

 

 

 

 

 

 

 

 

 

 

 

NTCIP Object Reference - Coordination Modes+ (MM->2->1)

NTCIP Coordination is best learned by example because all of the parameters in this section of the Version 50 menu are interrelated.  However, we suggest that you first have a brief look at the menu definitions in this section before working through the coordination examples and exercises provided in the TecNotes. 

Test OpMode

2.5.1 COORD OPERATIONAL MODE PARAMETER - The Operational Mode object  sets the active operation of the controller to:

       0 - Automatic (or "standby operation" - determined by current schedule or closed loop operation)

1-253 - Manual Pattern (user entry in this field overrides Automatic operation)

    254 - Manual Free operation

    255 - Manual Flash operation

Force-Off

2.5.4 COORD FORCE MODE PARAMETERS - The NTCIP Force-Off setting are FIXED, FLOAT or OTHER.  The OTHER setting enables the Force-Off+ and Easy Float settings on the right page of this menu as indicated in the notes above.

Phases may be terminated by a force-off issued by the coordinator or by the current max timing in effect.  Force-offs are calculated internally using the pattern sequence and split times for the active pattern.  Max timing under FIXED applies the Maximum mode programmed from this menu (see below). Max timing under FLOAT applies a floating max value (FloatMx) discussed in the Easy Calcs menu (MM->2->8->2).

The difference between FIXED and FLOAT force-offs is in the way unused time from the non-actuated signal phases is transferred to the other phases. FIXED force-offs allow each succeeding  phase to utilize all available "slack time".  FLOAT force-offs transfer "slack" time" to the designated coord phase (typically the major street in an arterial system). 

FLOAT force-offs are illustrated below.  FIXED force-offs are illustrated with the Maximum mode setting also programmed from this menu.

 

Correction

2.5.2 COORD CORRECTION MODE PARAMETERS - The Correction Mode parameter controls the method that the controller uses to correct the offset ("get in step" with the current time base reference).  The two allowable menu settings are:

  • LONG - (addOnly) the coordinator establishes a new offset by adding to timings in a manner that lengthens cycle time until the desired offset is achieved. 

  • SHORT/LONG - (called shortway in NTCIP) the coordinator determines the quickest way to "get in step"  by shortening or lengthening the split times to correct the offset.  The amount of correction (split time adjustment) is variable based on the transition factors programmed in MM->2->5.  These short/long transition values are typically set to 17% so the controller can "get in step" within 5 cycles after a pattern change.
     

  • DWELL - (dwell) the coordinator transitions to the new offset by dwelling in the coord phase until the desired offset is reached

NTCIP allows a third offset correction mode, termed DWELL that allows the coordinator to dwell in the coordinated phases a specified number of seconds each cycle until the desired offset is reached.  DWELL is not an option in this menu but is achieved by programming zero values for the "Short" and "Long" transition values and the desired "dwell" correction value under menu MM->2->5.

Note: NTCIP  defines the correction mode as other, dwell, shortway and addOnly.  Naztec fully supports this object in the database; however, the menu description was changed to LONG and SHORT/LONG rather than SHORTWAY and ADDONLY because traffic engineers are more familiar with these terms and definitions.

Maximum

2.5.3 COORD MAXIMUM MODE PARAMETERS - NTCIP defines this object to control which max time is used (if any) during coordination.  The valid selections for this object are:

  • MAX1 - Maximum 1 timing is effective when coordination is active

  • MAX2 - Maximum 2 timing is effective when coordination is active

  • MAX_ INH - Maximum timing is inhibited when coordination is active

These max settings are ineffective if the Force-Off setting is FLOAT because FLOAT uses a calculated FloatMax value equal to the split time minus the vehicle clearance times.

FlshMode

Naztec MIB - This is essentially the same datapoint as the Flash Mode under menu MM->1->4->1.  It was also placed on this screen responding to a customer request.

The Flash Mode controls whether Automatic Flash is implemented through the load switch channels (CHANNEL or Ø/OLAP mode) or through the cabinet facility (VOLT-MON mode).