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Chapter 3: SYSTEM OPERATION OUTLINE
4. SPEAKEr lINE fAIlurE DETEcTION mETHODS
3-6
4. SPEAKER LINE FAILURE DETECTION METHODS
Note
The failure detection functions described here are designed to perform on a 100-volt line of speaker. for the
methods using a 70- or 50-volt line, please consult your TOA dealer.
4.1. Impedance Detection Method
The VX-200SZ 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 checks the impedance
before the [SP OuT] terminal, and compares it with the initially set impedance to detect speaker line failures.
The VX-200SZ module's initial impedance value must be set at the time of installation or during periodic service
maintenance.
refer to
for the initialisation method.
[VX-200SZ Failure detection]
[VX-200SP Failure detection]
VX-2000SF
VX-200SZ
Ground fault
detection
Short/open circuit detection
through impedance detection
SP OUT
PA IN
PA LINK
40 Hz
Pilot Tone
VX-2000SF
VX-200SP
Ground fault
detection
Short/open circuit
detection
SP OUT
LINE MONITOR
End of line
PA IN
PA LINK
20 kHz
Pilot Tone
4.2. Pilot Tone Detection Method
The VX-200SP Pilot Tone Detection module detects speaker line failures by using a pilot tone. A 20kHz failure
detection pilot signal is superimposed on the signal line. To detect speaker line failures, the VX-200SP checks
the signal return from the speaker line end to the lINE mONITOr terminal.
Summary of Contents for VP-2241
Page 12: ...Chapter 1 Note...
Page 17: ...Chapter 2 ProduCt desCriPtioNs...
Page 41: ...3 1 Chapter 3 system oPeratioN outliNe...
Page 56: ...Chapter 4 FuNCtioNs...
Page 73: ...Chapter 5 oPeratioN...
Page 112: ...Chapter 6 FloWCHart From system setuP to oPeratioN...
Page 116: ...Chapter 7 PC soFtWare oFFliNe settiNGs...
Page 179: ...Chapter 8 iNstallatioN aNd settiNG ProCedures HardWare...
Page 223: ...Chapter 9 CoNNeCtioNs...
Page 266: ...Chapter 10 PC oNliNe CHeCKs aNd adJustmeNts...
Page 282: ...Chapter 11 otHer PC soFtWare FuNCtioNs...
Page 292: ...Chapter 12 aPPeNdiX...
Page 298: ...Chapter 13 sPeCiFiCatioNs...
Page 328: ...url http www toa jp 201409...