Wet contact with external DC power source to supply a relay.
DI-
DO+
DI+
DO-
PE
Dry contact and using camera's DO+ to supply a relay.
DI-
DO+
DI+
DO-
PE
Switch
NO
NC
Relay
External Device
Switch
NC
NO
Relay
External Device
DC 0V
DC
External DC power
External AC power
with Protected Earth
AC
PE
External AC power
with Protected Earth
AC
PE
VIVOTEK
User's Manual - 13