Sometimes it’s necessary to suspend the pump. In cases of disconnecting, or if there is an impending low. (however a temp basal is better is most cases as there is no chance of forgetting the suspend and going into DKA!)
From a blank screen, push ACT. Scroll down to SUSPEND.
Push ACT to suspend, or stop the pump.
Pump is STOPPED. Note the filled in circle at the top. This indicates there is no insulin flowing. It’s good to teach the T1Ds to look for this and let someone know if they see it! 
To cancel the SUSPEND, and get back to delivery of insulin, just push ACT for the screen instructions to appear, and then ACT again to confirm the restart of the basal insulin.
Darwin the Diabetic Alert Dog 