Output types
vhfBridge has 8 potential outputs for connection to a VHF radio transmitter.
There are two types of outputs:
The positive trip (high-potential output) does not supply voltage in the normal state. As
soon as an alarm or event occurs, the output supplies a voltage of 12–14 V
⎓
. The
negative trip (low-potential output) works the other way around. In the normal state, the
voltage is maintained at 12–14 V
⎓
, and when an alarm or event occurs, the voltage
drops to 0 V.
The vhfBridge output type and alarm pulse duration are con gurable in Ajax
apps.
VHF transmitter power supply
vhfBridge can supply a third-party VHF transmitter with 12 V
⎓
power (maximum
output current 2 A).
If the VHF transmitter has a current consumption of more than 2 A, it can be
powered by the vhfBridge battery. In this case, disable battery charge tracking in
the vhfBridge settings so that the system users do not receive noti cations
about the vhfBridge battery charging too long.
vhfBridge event transmission to the monitoring station
Ajax security system can also connect to the CMS and transmit alarms to the
monitoring station in Sur-Gard (Contact ID), SIA (DC-09), and other proprietary
protocol formats. See a complete list of supported protocols
The vhfBridge loop (zone) number can be found in the device states:
1. High potential output (positive trip).
2. Low potential output (negative trip).
