Follow the steps
Open the Prismatic.CATProduct document.
Click the Prismatic Joint icon in the Kinematics Joints toolbar or select Insert -> New Joint ->Prismatic from the Menu bar. The Joint Creation:
Prismatic dialog box appears.
Click New Mechanism.The Mechanism Creation dialog box is displayed:
enter a meaningful name for the mechanism. Click Ok when done.
The Following Dialog Box appears
Select Line 1 in the geometry area. In our example select an edge (fix.1)
Select Line 2 in the geometry area. Select a second edge (slot.1)
Select Plane 1 and Plane 2 as shown below:
Click Ok to end the prismatic joint creation.
Check "Length Driven"
The prismatic joint is created and identified in the specification tree.
Now lets simulate it.
Double Click Prismatic Joint Enter the length driven value. Press Ok
You will get message as "Mechanism can be simulated"