This option helps prevent manual cycle-start before closing collet.
Second-op jobs often require the operator to open collet, replace finished part with next part, clamp collet, then start the cycle. If the operator doesn’t press the collet clamp push button before pressing the cycle start buttons, the cycle will begin with collet open.
The pressure switch monitors the collet-clamped pressure, and disables palm-box cycle-start buttons if collet is not clamped.