Bosch Appliances Home Security System D9412GV2 Manual Do Utilizador

D9412GV2/D7412GV2 | Operation and Installation Guide | 7.0  Telephone Connections 

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Bosch Security Systems, Inc. | 5/05 | F01U003641B 

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7.11  D928 Dual Phone Line Switcher 

7.11.1 Description 

The optional D928 Dual Phone Line Switcher allows 
the control panel to send reports over two separate 
telephone lines. The control panel monitors both lines. 
If a line generates a signal and the control panel senses 
that a line is bad, the control panel attempts to use the 
other telephone line to send the message. If trouble is 
detected, the control panel keeps the faulty telephone 
line in memory.  

Set the Ring Count above 2 on Answering 
Machines: The control panel’s RPS line monitor 
feature might not operate correctly if an answering 
machine with a ring count of less than two rings is 
connected to a telephone line used by the D928 
Module. 

7.11.2 Operation 

Refer to Phone in the D9412GV2/D7412GV2 Program 
Entry Guide (P/N: F01U003636) for telephone 
supervision and reporting options. To use the D928, set 
the 

Two Phone Lines

 prompt to 

Yes. 

When the D928 is installed, the control panel alternates 
between Phone Line 1 and Phone Line 2 to send its 
first report. For example, on day one, the control panel 
first attempts to communicate on Phone Line 1. On 
day two, the control panel switches and attempts to 
communicate on Phone Line 2. 

 

 

Any time the control panel resets or is 
powered down or up, the next reported event 
always attempts to call out on Phone Line 1 
first. 

 

 

 

If Phone Line 2 is not in service on “Day 2”, 
the control panel switches to the primary 
phone line to send the report. 

With the D928 Dual Phone Line Switcher installed, the 
control panel uses two telephone lines (primary and 
secondary) to dial up to four telephone numbers. 

When using a primary and a backup device within a 

Route Group #

, the control panel makes two attempts 

on the primary telephone line using the 

Primary 

Device #

 as programmed. If these two attempts fail, 

the control panel switches to the secondary telephone 
line using the 

Backup Device #

 as programmed. This 

pattern continues for a total of ten attempts. After ten 
unsuccessful attempts, the control panel generates a 

Comm Fail

 event for the given 

Route Group #

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Figure 9: 

D928 Dual Phone Line Switcher 

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