This blog episode will demonstrate how to connect an additional push button to existing access control system. There are two connection type of the push button, first is the NC or Normally Close and the second is the NO or the Normally open connection. Below is to give you an idea what does these connections means;
Normally open – Is a contact that does not flow current in its normal state. Energizing it and switching it on will close the contact, causing it to allow current flow. in short this connection is open circuit or there is no continuity when you tested it using ohmeter.
Normally closed – Is a contact that flows current in its normal state. Energizing it and switching it on will open the contact, causing it to not allow current flow. In short this connection is short circuit or there is approximately zero ohm continuity when tested it using ohmeter.
The Diagram below shows that when the access control system has a push button in a Normally open connection then the additional push button will be connected in parallel.
The Diagram below shows that when the access control system has a push button in a Normally close connection then the additional push button will be connected in series.
