Using Simulink

Displaying a Block

To determine the block in a model's diagram that corresponds to a particular index, enter bshow s:b at the command prompt, where s:b is the block index. The bshow command opens the system containing the block (if necessary) and selects the block in the system's window.

Displaying a Model's Nonvirtual Systems

The systems command displays a list of the nonvirtual systems in the model being debugged. For example, the Simulink clutch demo (clutch) contains the following systems:

• sldebug clutch
  [Tm=0                      ] **Start** of system 'clutch' outputs
  (sldebug @0:0 'clutch/Clutch Pedal'): systems
   0   'clutch'
   1   'clutch/Locked'
   2   'clutch/Unlocked'
  

Note    The systems command does not list subsystems that are purely graphical in nature, that is, subsystems that the model diagram represents as Subsystem blocks but that Simulink solves as part of a parent system. In Simulink models, the root system and triggered or enabled subsystems are true systems. All other subsystems are virtual (that is, graphical) and hence do not appear in the listing produced by the systems command.

Displaying a Model's Nonvirtual Blocks

The slist command displays a list of the nonvirtual blocks in a model. The listing groups the blocks by system. For example, the following sequence of commands produces a list of the nonvirtual blocks in the Van der Pol (vdp) demo model.

• sldebug vdp
  [Tm=0                      ] **Start** of system 'vdp' outputs
  (sldebug @0:0 'vdp/Integrator1'): slist
  ---- Sorted list for 'vdp' [12 blocks, 9 nonvirtual blocks, 
  directFeed=0]
    0:0    'vdp/Integrator1' (Integrator)
    0:1    'vdp/Out1' (Outport)
    0:2    'vdp/Integrator2' (Integrator)
    0:3    'vdp/Out2' (Outport)
    0:4    'vdp/Fcn' (Fcn)
    0:5    'vdp/Product' (Product)
    0:6    'vdp/Mu' (Gain)
    0:7    'vdp/Scope' (Scope)
    0:8    'vdp/Sum' (Sum)
  

Note    The slist command does not list blocks that are purely graphical in nature, that is, blocks that indicate relationships or groupings among computational blocks.

Displaying Blocks with Potential Zero Crossings

The zclist command displays a list of blocks in which nonsampled zero crossings can occur during a simulation. For example, zclist displays the following list for the clutch sample model:

• (sldebug @0:0 'clutch/Clutch Pedal'): zclist
    2:3    'clutch/Unlocked/Sign' (Signum)
    0:4    'clutch/Lockup Detection/Velocities Match' (HitCross)
    0:10   'clutch/Lockup Detection/Required Friction
             for Lockup/Abs' (Abs)
    0:11   'clutch/Lockup Detection/Required Friction for 
             Lockup/ Relational Operator' (RelationalOperator)
    0:18   'clutch/Break Apart Detection/Abs' (Abs)
    0:20   'clutch/Break Apart Detection/Relational Operator'
             (RelationalOperator)
    0:24   'clutch/Unlocked' (SubSystem)
    0:27   'clutch/Locked' (SubSystem)
  

Displaying Algebraic Loops

The ashow command highlights a specified algebraic loop or the algebraic loop that contains a specified block. To highlight a specified algebraic loop, enter ashow s#n, where s is the index of the system (see Identifying Blocks in Algebraic Loops) that contains the loop and n is the index of the loop in the system. To display the loop that contains the currently selected block, enter ashow gcb. To show a loop that contains a specified block, enter ashow s:b, where s:b is the block's index. To clear algebraic-loop highlighting from the model diagram, enter ashow clear.

Displaying Debugger Status

In GUI mode, the debugger displays the settings of various debug options, such as conditional breakpoints, in its Status panel. In command-line mode, the status command displays debugger settings. For example, the following sequence of commands displays the initial debug settings for the vdp model.

• sim('vdp',[0,10],simset('debug','on'))
  [Tm=0                      ] **Start** of system 'vdp' outputs
  (sldebug @0:0 'vdp/Integrator1'): status
    Current simulation time: 0 (MajorTimeStep)
    Last command: ""
    Stop in minor times steps is disabled.
    Break at zero crossing events is disabled.
    Break when step size is limiting by a state is disabled.
    Break on non-finite (NaN,Inf) values is disabled.
    Display of integration information is disabled.
    Algebraic loop tracing level is at 0.
  

Displaying Information About the Model

Debugger Command Summary