Leader LT 4441, Instruction Manual

4. HOW TO USE 

22

4.5.3 

Setting Automatic Signal Switching 

Press AUTO SWITCHING to select whether the output signal will be switched 
automatically or not when an error is detected. This setting is the same for channels 1 to 
11. 

If you select SWITCH FAULT, the LT 4441/4442 will automatically switch to the other signal 
(primary or backup signal) when an error occurs in the output signal. Normally use this 
setting. 
If you select DISABLED, even if an error occurs in the output signal, the signal will not be 
switched automatically. Use this setting when you want to just detect errors. 

Figure 4-12  AUTO SWITCHING 

Depending on the AUTO SWITCHING setting and the MODE DIP switch setting, the 
operation of the LT 4441/4442 differs as shown below. 

For details on the MODE Dip switch setting, see section 4.3.6, “Operation Mode and the Standby Time 
Settings.” 

Table 4-8    LT 4441/4442 operations 

LT 4441/4442 Setting 

When SYNC SOURCE is PRIMARY 

When SYNC SOURCE is BACKUP 

AUTO 

SWITCHING 

MODE 

Input Signal 

State 

Output Signal 

SYNC SOURCE 

Key Operation 

Output Signal 

SYNC SOURCE 

Key Operation 

Normal 

Remains PRIMARY 

Switches to BACKUP

Remains BACKUP 

Switches to PRIMARY

BACKUP error 

Remains PRIMARY 

Remains PRIMARY 

Switches to PRIMARY 

Remains PRIMARY 

PRIMARY error 

Switches to BACKUP

Remains BACKUP 

Remains BACKUP 

Remains BACKUP 

SWITCH 

FAULT 

NORMAL 

OVERRIDE 

Errors on both 

Remains PRIMARY 

Switches to BACKUP

Remains BACKUP 

Switches to PRIMARY

Normal 

Remains PRIMARY 

Switches to BACKUP

Remains BACKUP 

Switches to PRIMARY

BACKUP error 

Remains PRIMARY 

Remains PRIMARY 

Remains BACKUP 

Switches to PRIMARY

PRIMARY error 

Remains PRIMARY 

Switches to BACKUP

Remains BACKUP 

Remains BACKUP 

NORMAL 

Errors on both 

Remains PRIMARY 

Switches to BACKUP

Remains BACKUP 

Switches to PRIMARY

Normal 

Remains PRIMARY 

Switches to BACKUP

Remains BACKUP 

Switches to PRIMARY

BACKUP error 

Remains PRIMARY 

Switches to BACKUP

Remains BACKUP 

Switches to PRIMARY

PRIMARY error 

Remains PRIMARY 

Switches to BACKUP

Remains BACKUP 

Switches to PRIMARY

DISABLED 

OVERRIDE 

Errors on both 

Remains PRIMARY 

Switches to BACKUP

Remains BACKUP 

Switches to PRIMARY