D9412G/D7412G Operation & Installation Guide
43488D
Page 34
© 2002 Radionics
D9412G/D7412G
Telephone Connections
6.6
Operation Monitor LED (Green)
The green Operation Monitor LED indicates the operation of the CPU (Central Processing Unit). When the CPU is
operating normally, the LED flashes 0.5 second on, 0.5 second off.
The green LED also serves as a ring indicator. The LED is located on the lower right side (see
Figure 9). When
there is ring voltage on the phone line (the phone is ringing), the green LED flickers at a faster rate for the duration
of each ring. Ring voltage must reach a minimum of 45 VAC before the system detects it.
6.7
Dialing Format
The system can be programmed to use DTMF or pulse dialing. See
Phone Parameters in the D9412G/D7412G
Program Entry Guide.
6.8
Phone Line Monitor
The panel has a built-in phone line monitor that tests the phone line for voltage. If the D928 Dual Phone Line
Switcher is used to connect two phone lines to the panel, the panel monitors both lines. The normal voltage on a
telephone line is approximately 48 VDC (24 VDC for some phone systems). The phone line monitor senses
trouble when the voltage on the line falls below 3.0 VDC.
If the monitor senses trouble, it starts a programmable phone line trouble timer. The timer continues to run as long
as the monitor senses trouble. It resets to zero when the panel senses a normal line. If the timer reaches the delay
time in the
Phone Supervision program item, it begins a phone line trouble response. Programming determines
what the response is. See
Phone Parameters in the D9412G/D7412G Program Entry Guide.
The panel stops monitoring the phone line during its phone line trouble response. If the response includes
sending a report, the panel does not resume monitoring until the report is acknowledged or it goes into
communication failure.
Bad line may test OK: The telephone line monitor uses voltage levels 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.
6.9
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. D9412G/D7412G firmware allows for “called party disconnect” by adding a 35
second “on hook” interval to the dial tone detect function. If the panel does not detect a dial tone in seven seconds,
it puts the phone line on hook for 35 seconds 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.
6.10
Communication Failure
After two attempts to reach the receiver, a
COMM FAIL PH #
event is generated. This event will tag along with the
original event.
After ten attempts to reach the receiver, the panel goes into communication failure. The panel clears any reports in
its phone buffer and
COMM FAIL RT #
event is generated, which appears in the display at command centers. A
trouble sounder can be programmed to annunciate at the command centers. An hour after the
COMM FAIL RT #
is
generated, the panel attempts to send this event, if programmed. If the
COMM FAIL RT #
event is the only event in
the queue and is unable to reach the central station, the command centers will not turn on the trouble sounder
again.
If the D928 Dual Phone Line Switcher is used, the D9412G/D7412G makes a total of ten attempts before going
into communication failure.
6.10.1 Enhanced Communication
The D9412G/D7412G Control/Communicator panels have the ability to transmit events over the SDI Bus to a
D9133TTL-E Network Interface Module. For more information on Enhanced Communications capabilities, please
refer to
RADXAUX1 in the D9412G/D7412G Program Entry Guide.
