Phone Line Fault; Called Party Disconnect; Communication Failure; Ground Start - Bosch D6412 Operation And Installation Manual

D6412/D4412
Telephone Connections
6.7

Phone Line Fault

The panel has a circuit that tests the phone line for voltage. Normal voltage on a telephone line is approximately 48 VDC
(24 VDC for some phone systems). The phone line monitor senses trouble when voltage drops low enough (between 1 V
and 3 V).
If the panel senses trouble, it starts a phone line trouble timer that continues to run as long as the panel senses trouble. It
resets to zero when the panel senses a normal line. If the timer reaches 40 sec., it begins a phone line trouble response.
Programming determines what the response is. See Phone Line Fault Response Options in the D6412/D4412 Program Entry
Guide (P/N: 45351).
Bad line may test OK: The telephone line test circuit uses the voltage level to test the status of the phone line. In some
instances, a given telephone line may be out of service without affecting the voltage on the line. The phone line monitor can
not recognize this trouble condition.
6.8

Called Party Disconnect

Telephone companies provide "called party disconnect" to allow the called party to terminate a call. The called party must go
on-hook (hang up) for a fixed interval before a dial tone is available for a new call. This interval varies with telephone
company equipment. The panel provides "called party disconnect" by adding a 35 sec. on hook interval to the dial tone detect
function. If the panel does not detect a dial tone in 7 sec., it puts the phone line on hook for 35 sec. to activate "called party
disconnect," goes off hook and begins a seven-second dial tone detect. If no dial tone is detected, the panel dials the number
anyway. Each time the number is dialed, the panel records this as an attempt.
6.9

Communication Failure

The panel routes reports to two routing destinations, each of which can be programmed with two phone numbers. See
Appendix A: Routing Dialing Tables in the D6412/D4412 Program Entry Guide (P/N: 45351). Numbers in [ ] are the numbers
assigned to panel events. For more panel event information, see Appendix B in the D6412/D4412 Program Entry Guide.
The Routing Dialing tables show the circumstances when Communication Failure Events are created. When a Comm Fail
occurs, the D6412/D4412 responds as follows:
1. Clear (dump) the initiating report and any pending reports from the dialer buffer for the destination
where the Comm Fail Event occurred.
2. Create a Comm Fail [69] Report or Alt Comm Comm Fail [70] Report that includes the Destination
Number (1 or 2). Modem IIIa² Reports report the destination number as a Route Group (RG). The
Alternate Comm Fail Report is used when an alternate communications path is used (e.g., SAFECOM).
3. Comm Fail, Comm Restoral [71], and Alternate Comm Restore [72] Reports follow the System Status
Reports routing.
4. If the Comm Fail occurred on Destination 1 and System Status Reports routing is set to Destination 2 or
set to Destination 2 on Destination 1 fail, then send Comm Fail Report.
5. If the Comm Fail occurred on Destination 1 and System Status Reports routing is set to Destination 1 then
send a Comm Restore Report with the next report for destination 1.
6. If the Comm Fail occurred on Destination 2 and System Status Reports routing is set to Destination 1,
then send Comm Fail Report.
7. If the Comm Fail occurred on Destination 2 and System Status Reports routing is set to Destination 2 then
send a Comm Restore Report with the next report for destination 2.
8. If a Comm Fail Report is sent successfully to the other destination, a Comm Restore Event should be sent
when there is a successful communication on the failed destination.
6.10

Ground Start

Some telephone systems require a momentary ground input to initiate a dial tone. To interface with a ground start system,
you must wire PO1 as shown in Figure 7. PO1 Jumper must be open.
6. 1 0. 1

Program PO1 for Ground Start

See Outputs of the D6412/D4412 Program Entry Guide (P/N: 45351) for programming instructions. PO2, PO3, and PO4 can
be used to interface with a ground start system using a D133 Relay Module or a D134 Dual Relay Module. The PO1 jumper
is not used when interfacing PO2, PO3, or PO4 to a D133 or D134. See Figure 7 for details.
45349E
D6412/D4412 Operation and Installation Guide
Page 24 © 2003 Bosch Security Systems