The combination of switching type and number of control groups gives rise to a natural number of regulating steps in the entrance zone. 

With the  On/Off  strategy and four control groups, it is possible to implement four regulating steps, for example.

The automatic positioning arranges the luminaires in clusters in accordance with their control group.

For example, an On/Off strategy with four control groups: 4-2-3-1 | 4-2-3-1 | 4-2-3-1......

In order to achieve the regulating steps, the control groups are switched off one after the other. In our example, each time a group is switched off, the luminous flux and hence the luminance level is reduced by 25%. At the lowest step, only the luminaires in Group 4 are still switched on.

Since the overall length of the adaptation zone is reduced when the entrance level is reduced, no luminaires from the higher-number group may be placed in the rear section of the tunnel. 

The overall picture is then as follows:

S1 = 100%

4-2-3-1 | 4-2-3-1 | 4-2-3-1......2-3-1 | 2-3-1.....2-1 | 2-1....1-1-1-1

S2 = 75%

4-2-3-X | 4-2-3-X | 4-2-3-X......2-3-X | 2-3-X.....2-X|  2-X....X-X-X-X

S3 = 50%

4-X-3-X | 4-X-3-X | 4-X-3-X......X-3-X | X-3-X.....X-X | X-X....X-X-X-X

S4 = 25%

4-X-X-X | 4-X-X-X | 4-X-X-X......X-X-X | X-X-X.....X-X | X-X....X-X-X-X

The individual switching strategies:

Switch ON / OFF :  See above. The number of regulating steps is identical to the number of control groups.

Switch ON /50%/ OFF :  This arrangement is identical to “Switch ON/OFF”, but since provision is made for an intermediate step, there are twice as many possible regulating steps as control groups.

Dim 50% :  It is assumed here that the luminance levels of between 100% and 50% are achieved through dimming. After this, half the luminaires in a cluster are switched off, and the remaining luminaires are dimmed in the 100%-50% range again, which now corresponds to a luminance level of 50%-25%. The “width” of the clusters, however, is now 2 ^(n-1)   (n= number of control groups) For example, with three control groups, it is possible to achieve the 50% and 25% levels by switching:

S1 = 100%

3-1-2-1 | 3-1-2-1|3-1-2-1......2-1|2-1....1|1

S2 = 50%

3-X-2-X | 3-X-2-X|3-X-2-X......2-X|2-X....X|X

S3 = 25%

3-X-X-X | 3-X-X-X|3-X-X-X......X-X|X-X....X|X

In this case, it is now possible to dim down to 12.5% of the initial luminance level.

Dim 30% :  It is assumed here that the luminance levels between 100% and ~30% are achieved by dimming. After this, 2/3 of the luminaires in a cluster are switched off and the remaining luminaires dimmed in the 100%-30% range, which now corresponds to a luminance level of ~30%-~10%. The “width” of the clusters is now 3 ^(n-1)   (n= number of control groups). For example, with three control groups, it is possible to switch down to levels of 30% and 10%.

S1 = 100%

3-1-1-2-1-1-2-1-1 | 3-1-1-2-1-1-2-1-1|......2-1-1|2-1-1....1|1

S2 = 30%

3-X-X-2-X-X-2-X-X | 3-X-X-2-X-X-2-X-X|......2-X-X|2-X-X....X|X

S3 = 10%

3-X-X-X-X-X-X-X-X | 3-X-X-X-X-X-X-X-X|......X-X-X|X-X-X....X|X

Note:  The maximum distances for the highest control group at the start of the tunnel are limited by the uniformity required at the lowest regulating step. As a result, the maximum cluster width and hence the number of control groups is generally limited. Please also note the specifications concerning the  “Maximum distance between luminaires”  for automatic positioning.

Note:  The patterns listed here are used as defaults by the program and provided with the appropriate support for  “Automatic positioning” . Independently of this, the user can set up additional regulating steps in the dialog or adjust the intermediate values through individual dimming settings for each regulating step.

Note:  At all events, the user must make sure that the prescribed uniformities and required levels are achieved and must monitor these. The automatic positioning facility cannot guarantee this, and it may be necessary to position an additional row, etc.