Toa VM-3000 Series - Manual (Page 128)

128
VM-3240VA/3360VA/3240E/3360E
(+)
Relay Control
(–)
N
C
SP
Speaker
Attenuator
14.8.3. External attenuator connection (4-wire system)
Two types of attenuators are connectable to this unit, one to be bypassed when 24 V DC is applied to the attenuator,
and the other to be bypassed when the 24 V DC being normally applied to is cut off (in no voltage mode).
Connections of the unit's attenuator control output and 24 V DC output terminals differ depending on the
attenuator types as shown below.
[Example 1]
Operation status of the VM amplifier and the corresponding attenuator operation
VM-3240VA/3360VA/3240E/3360E
(+)
Relay Control
(–)
N
C
SP
Speaker
Attenuator
Note
The system in Example 2 is more fail-
safe than that in Example 1.
Operation status of VM amplifier Applied voltage to the attenuator Attenuator operation
Normal mode No-voltage Normal operation
At the time of emergency broadcast, or
24 V DC Bypassed
Priority 1 or 2 broadcast
Operation status of VM amplifier Applied voltage to the attenuator Attenuator operation
Normal mode 24 V DC Normal operation
At the time of emergency broadcast, or
No-voltage Bypassed
Priority 1 or 2 broadcast
[Example 2]
Operation status of the VM amplifier and the corresponding attenuator operation