4. HOW TO USE
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4.7
LT 4446/4447 Configuration
4.7.1
Setting the Key Lock
The LT 4446/4447 locks its keys after 1 minute of inactivity (no key operations). When the
key lock is on, front-panel key operations are not accepted.
To perform front-panel key operations, turn the key lock off. Hold down the KEY LOCK key
for 3 seconds to turn the key lock on and off.
Figure 4-12 Key lock
4.7.2
Switching the Output Signal
The SYNC SOURCE area shows the signal that is being transmitted through the output
connector (PRIMARY or BACKUP). The setting is shared among channels 1 to 11.
You can press the key to manually switch the output signal. However, you may not be able
to switch the signal depending on the LT 4446/4447 state. For details, see section 4.7.3,
"Setting Automatic Signal Switching."
SYNC SOURCE is set to PRIMARY immediately after the LT 4446/4447 turns ON.
Figure 4-13 SYNC SOURCE
4.7.3
Setting Automatic Signal Switching
In the AUTO SWITCHING area, select whether the output signal will be switched
automatically when a fault is detected in the input signal. The setting is shared among
channels 1 to 11.
If you select SWITCH FAULT, the LT 4446/4447 will automatically switch to the other signal
(PRIMARY or BACKUP) when a fault is detected in the output signal. Normally use this
setting.
Select DISABLED to not switch the output signal automatically even when a fault is
detected. Use this setting when you want to just detect faults.
Figure 4-14 AUTO SWITCHING
USO
RESTRITO
