fischertechnik COMPUTING ROBO TX ElectroPneumatic, Manual

ROBO TX ElectroPneumatic

COMPUTING

14

Tips

The position of the gripper arm can be defined with the aid of the "pulse counter" command. The values 
required can be entered in the interactive window. 
If the ideal position is between two pulses, you can also adjust the start or end position of the balls by 
moving one or more of the building blocks so that the gripper picks up or puts down the ball reliably.

Information on the commands used is given in  

ROBO Pro help

 Chapters 3. and 8.1.10. 

Variables

Task 3 - Two balls in obstacle course - ROBO Pro Level 3 

Now two balls roll through the obstacle course. Two conditions should be fulfilled to ensure that the 
robot distributes the balls uniformly on the two tracks: 

Balls arriving at the bottom end points (P1 or P2) should be transported alternately to the upper 

• 

starting points (P3 or P4).
If balls are present simultaneously at both end points (P1 and P2), they should also be 

• 

picked up alternately. 

You can meet these requirements by supplementing the program.

Tips 

So-called variables help to solve this problem. Information on what variables are and how they can be 
used is given in the  

ROBO Pro help 

in Chapter 5. It is important that you switch to level 3 in ROBO Pro.

Here is the solution:
Define a variable (Pos1 – Pos4) for each of the 4 positions P1, P2, P3 and P4. When a position is reached, 
set the value for the associated variable to 1 to help you remember the position moved to last.

Example: 

First ball:

Variable  

Value

Variable

Value

Ball present at P1 

Pos1 

= 

1 

Pos2 

= 

0

Ball moved to P3  

Pos3 

= 

1 

Pos4 

= 

0

Second ball:

Ball present at P1 and P2. Since Pos1=1, the robot should now go to P2. Then Pos1 is set to 0 and Pos2 
to 1. Since the ball was set down at P3 during the first operation (Pos3 = 1), the ball is now transported 
to P4. Then Pos1 is set to 0 and Pos2 to 1.
 
Too complicated? You can call a finished example program for this task with this symbol.

Attempt to understand how the principle works by looking at the final sequence.

ball obstacle course_3.rpp