Use Cases for Prefer Route

Constraint

How wiring synthesis applies a Prefer Route constraint can depend on the particular scenario.

Prefer Route Constraint Not Defined

Figure 107: Constraint Not Defined Example - Capital Logic Designer Design

Figure 108: Constraint Not Defined Example - Capital Systems Integrator Design

Wiring synthesis uses the cheapest route.

Figure 109: Constraint Not Defined Example - Routing Solution

After wiring synthesis, the system considers the signal as routed.

Preferred Route in All Configurations

Figure 110: In All Configurations Example - Capital Logic Designer Design

Figure 111: In All Configurations Example - Capital Systems Integrator Design

Prefer route constraint applied to red bundle: Prefer route in configuration where Signal matches Name = COND1

Wiring synthesis routes the signal through the preferred route.

Figure 112: In All Configurations Example - Routing Solution

After synthesis, the system considers the signal as routed.

Note

This is applicable only if the preferred route is considered as a potential routing solution by wiring synthesis.

Preferred Route in a Subset of Configurations

Figure 113: In Subset of Configurations Example - Capital Logic Designer Design

Figure 114: In Subset of Configurations Example - Capital Systems Integrator Design

Constraint applied to red inline half (J3): Prefer route in configuration LHD where Signal matches Name = COND1

Wiring synthesis routes the signal through the preferred route.

Figure 115: In Subset of Configurations Example - Routing Solution

Note

This is applicable only if the preferred route is considered as a potential routing solution by wiring synthesis.

After synthesis, the system considers the signal as routed. However, the signal does not route through J3 when DEV100 is not active, so the LHD configuration is necessary for the correct routing of the signal between DEV101 and DEV102.

Preferred Route Applicable for Too Many

Configurations

Figure 116: Applicable for Too Many Configurations Example - Capital Logic Designer Design

Figure 117: Applicable for Too Many Configurations Example - Capital Systems Integrator Design

Constraint applied to red inline half (J3): Prefer route in configuration where Signal matches Name = COND1

In the configurations where DEV100 is not active, the routing solution depends on the object on which the Prefer Route constraint is defined:

• If the object is on a route not considered by synthesis, the cheapest routing solution will be used.

• If the object is on a route considered by synthesis, the route containing this object will be used (if that route is allowed).

In this example, the routing solution when DEV100 is not active will loop around using the inline:

Figure 118: Applicable for Too Many Configurations Example - Routing Solution

In configurations where DEV100 is not active, it may be that the routing solution does not use the object on which the Prefer Route constraint is defined. In this case, the synthesis output and the Design Assistant report the signal’s route state as “Routed (non-preferred) for those configurations.

Preferred Route with Variant Placement

Figure 119: Variant Placement Example - Capital Logic Designer Design

Figure 120: Variant Placement Example - Capital Systems Integrator Design

Constraint applied to red highlighted inline: Prefer route in configuration where Signal matches Name = COND1

Constraint applied to blue highlighted inline: Prefer route in configuration where Signal matches Name = COND1

Wiring synthesis routes the signal through the preferred route in the appropriate configuration.

Figure 121: Variant Placement Example - Routing Solution

Note

This is applicable only if the preferred route is considered as a potential routing solution by wiring synthesis.

After synthesis, the system considers the signal as routed. However, the signal does not route through J1 when DEV100-LHD is not active, so the LHD configuration is necessary for the correct routing of the signal between DEV100-LHD and DEV101-LHD. The signal does not route through J2 when DEV100-RHD is not active, so the RHD configuration is necessary for the correct routing of the signal between DEV100-RHD and DEV101-RHD

Preferred Route Is Not Considered by

Synthesis

In this example, end points are present at the front of the vehicle (orange circles).

A Prefer Route constraint is applied to a bundle at the rear of the vehicle (blue circle).

Figure 122: Route Not Considered Example

The Prefer Route constraint matches the signal connected to the devices at the front of the vehicle. No other constraints have been applied that affect the routing of the signal.

The object with the applied Prefer Route constraint is not considered by synthesis, so the preferred route is not used.

After wiring synthesis, the signal has the route state of ‘Routed (non-preferred),”:

• Synthesis reports that the signal has not followed the preferred route.

• Design Assistant reports signals with route state of ‘Routed (non-preferred)’.

In the case that a preferred route is never used, the ‘Preferred route is never used’ design rule check will report an error.

Preferred Route has ‘Don’t Route’ Constraint

Applied

Figure 123: Don’t Route Constraint Applied Example

The ‘Prefer Route’ and ‘Don’t Route’ constraint are applied on the same route, on either the same or different objects. For example, the Prefer Route constraint may be set on a bundle connecting to an inline, and the Don’t Route constraint may be set on the inline.

Both constraints match the same signal. The object on which the Prefer Route constraint is defined is considered by synthesis.

The Don’t Route constraint takes priority over the Prefer Route constraint.

After wiring synthesis, the signal has the route state of ‘Routed (non-preferred)’:

• Wiring synthesis reports that the signal has not followed the preferred route.

• Design Assistant reports signals with route state of ‘Routed (non-preferred)’.

In the case that a preferred route is never used, the ‘Preferred route is never used’ design rule check will report an error.

Parent Topic:

Prefer Route Constraint for Defining a Preferred Route for a Signal

Capital Systems Integrator User Guide, 2512.2606

Unpublished work. © 2026 Siemens