Toa VX-2000SF - Impedance Detection Method

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5.2.ImpedanceDetectionMethod
The VX-200SZ-2 Impedance Detection module compares impedances to detect speaker line failures. A 40Hz
pilot signal for impedance detection is superimposed on the signal line. The VX-200SZ-2 checks the impedance
beforethe[SPOUT]terminal,andcomparesitwiththeinitiallysetimpedancetodetectspeakerlinefailures.
The VX-200SZ-2 module's initial impedance value must be set at the time of installation or during periodic
service maintenance.
The VX-200SZ-2 can connect 2 speaker lines that work simultaneously during paging.
Bothlines(orSPOUTAandB)cannotbeprogrammedasindividualcallzones.
Once the line is shorted, it remains disconnected from the speaker output until resetting.
Once the line is opened, it will be automatically monitored every hour to see if the line is recovered.
Refer to the VX-2000 series Instruction manual.
[VX-200SZ-2 Failure detection]
VX-2000SF
VX-200SZ-2
Ground fault
detection
Short/open circuit detection
through impedance detection
SP OUT (A)
SP OUT (B)
Speaker line A
Speaker line B
PA IN
PA LINK
40 Hz
Pilot Tone
Notes
• Observe the following relationship between the amplifier's power output and connected speaker's input
power:Amplifierwattage≥SpeakerwattageonthespeakerlineA+SpeakerwattageonthespeakerlineB
• MakethespeakerwattageoneachofthespeakerlinesAandBalmostthesame(within10%).