Experiment: Control Using an Emergency Shut-off Switch

The following experiment provides an example of a control mechanism that can be reset to a specified initial condition (cylinder retracted) at any time by means of an emergency shut-off switch (S1). Once the switch is opened, no movement may be permitted until after restarting by means of push-button S3.

Construct the pneumatic circuit illustrated below and create a flow diagram using the flow diagram editor (note: since the emergency shut-off S1 is designed as a changeover switch, it needs to be represented in the editor by two components, one normally open and one normally closed; note also that the normally open contactor B1.1 is shown activated in the diagram). You can click on the graphic to open it in a separate window: