APPENDIX
DRY CONTACT
A dry contact means that no electricity is connected to it. It is prepared for free connections. The Relay
Output contacts provided in this keypad system are dry contacts.
N.C.
Normally Closed, the contact is closed circuit at normal status. It is open circuit when active.
N.O.
Normally Open, the contact is open circuit at normal status. It is closed circuit when active.
TRANSISTOR OPEN COLLECTOR OUTPUT
An open collector output is equivalent to a Normally Open (N.O.) contact referring to ground similar to a
relay contact referring to ground. The transistor is normally OFF, and its output switches to ground (-) when
active. The open collector can only provide switching function for small power but it is usually good enough
for controlling of an alarm system. The Duress, Inter-lock and Key Active/Alarm Outputs of the keypad are
open collector outputs.
OPEN COLLECTOR
OUTPUT ----
Output switches to
ground when activated
N.O. CONTACT
OUTPUT ----
Output switches to
ground when activated
EQUIVALENT
42
7380 S. Eastern Avenue, Suite 124-320
Las Vegas, NV 89123
www.transmittersolutions.com
