Instruction manual

Page 1018 of 3156 China – Supervised Analog Lines
553-3001-306 Standard 10.00 January 2002
In the idle state, the analog port in the Meridian 1 provides ground signal on
the tip lead and battery on the ring lead. This polarity is maintained during
dialing and ringing at the far end. When the far end answers, the battery and
ground connections are reversed. The reverse battery is maintained while the
call is established. When the far end disconnects, the battery and ground
connections are reverted to the idle state to signal that the far end has
disconnected. If the terminal device disconnects first, the Meridian 1 sends
the Deactivate Battery Reversal Scan Signal Distribution (SSD) message to
the firmware after receiving the on-hook status to revert the polarity to its idle
state.
Two types of battery reversal are supported. Battery Reversal for Absolute
Answer Only provides an answer supervision signal to the terminal device
only when the Meridian 1 detects an absolute answer. Battery Reversal for
Absolute and Assumed Answer provides an answer supervision signal to the
terminal device even when an assumed answer is detected and the far end is
not capable of indicating definite answer (for example, an outgoing call on an
unsupervised loop start trunk).
Hook Flash Disconnect Supervision
Hook flash disconnect supervision is used for incoming calls terminating at
the terminal device. The disconnect signal is indicated by the removal of the
ground connection to the tip lead for a specific period of time, which is
provided by firmware ranging from a minimum of 10 milliseconds to a
maximum of 2.55 seconds. The analog port is held busy for incoming calls
while hook flash is in progress.