scan topic not providing any data

edit

Hi, (i have edited the post providing more detail of problem)

i am using turtlebot 2 with astra pro sensor on ubuntu 14 with ros indigo.

Edit

thanks all for reply. Here is the detail.

machine 1: windows 10 with MatLab 2017

machine 2 (turtlebot pc): ubuntu 14 with ROS indigo attached with TURTLEBOT 2 and ROS ASTRA PRO.

both machines can ping each other and i can see the rostopics from Matlab machine node also. I run following commands on machine 1

$ roscore
$ roslaunch turtlebot_bringup minimal.launch

i am activating my 3d sensor "orbbec astra pro" using following command

$ source devel/setup.bash
$rosrun astra_camera create_udev_rules
$roslaunch astra_launch astra_pro.launch

I was trying to run MatLab code from explore basic behaviour of turtlebot example on machine 2 . and i got MatLab error at code line laser = rossubscriber('/scan'); while I was not getting /scan topic listed on MatLab output for rostopic list also. then I executed the following command also on machine 1 and executed again Matlab code on pc2. and this time i resolved this problem and listed /scan topic also in rostopic list on Matlab output successfully.

$ roslaunch turtlebot_rviz_launchers view_navigation.launch

but now i am stuck at next line of /scan topic code line

scan = receive(laser,10)

and getting timeout error message

Error using robotics.ros.Subscriber/receive The function did not receive any data and timed out.

i even tried and checked all help on my setup from these two threads link 1 and link 2. still, i am getting same timeout error message and i am not able to run code completely for turtlebot. when i printed its scan data variable that shows no data in the variable.

Error in LaserScanWondering (line 51)
scan = receive(laser,10)
>> showdetails(scan)

  AngleMin       :  0
  AngleMax       :  0
  AngleIncrement :  0
  TimeIncrement  :  0
  ScanTime       :  0
  RangeMin       :  0
  RangeMax       :  0
  Ranges         :  []
  Intensities    :  []
  Header            
    Seq     :  937437
    FrameId :  
    Stamp      
      Sec  :  0
      Nsec :  0

edited

when i run

$rosrun depthimage_to_laserscan depthimage_to_laserscan image:=camera/depth/image_raw

in turtlebot machine , i get no response/output whereas i can easily get rgb, ir and depth images using rosrun commands.

I am not using any LIDAR sensor, but can I get laser scan values from /scan topic of astra pro sensor? I am not using any customized code and i have also not edited any package values used. because they are read-only, Is there a way to modify the default values also? also when i run gampping or amcl package on turtlebot machine (in simulation or with real turtlebot) then my laser scan does not match with the map and it has overlapping values.