Matrix Visionpro System Manual page 45

• Open Loop Disconnect Timer (ms): This parameter is applicable only if the option Open Loop
Disconnect is selected as Disconnect Signaling type on the SLT port.
Open Loop Disconnect Timer is the time period for which the system will remove Battery Voltage on the
SLT port and restore Battery Voltage on the expiry of this timer to signal Call Disconnection.
The range of the timer is from 68 to 952ms with a gap of 68ms each between any two consecutive values.
• Loop Current (mA): The SLT Port provides Loop Current to the telephone instrument connected to the
port to drive it.
The Loop Current is to be increased/decreased according to the length of the telephony wiring cable
between the wall jack (into which the SLT telephone instrument is plugged) and the MDF (into which the
cables from the SLT port are terminated).
The longer the Loop Length of the SLT port, the greater the likelihood of current dissipation, affecting
speech quality of the telephone instrument connected to the SLT port.
The system supports Loop Current of 25, 30, 35 and 40mA. By default, the Loop Current for SLT port is set
to 25mA which is sufficient to support Loop Length of 1 kilometer.
You may change the Loop Current according to the Loop Length of the SLT.
• Loop Length: The Loop Length is the distance between the Central Office and the telephone instrument
connected to the SLT port. Select the Loop Length as Up to 5km or Above 5km according to your
installation scenario.
• Minimum Current for OFF-Hook Detection: VISIONPRO detects OFF-Hook state of an SLT instrument
and gives Dial tone on the basis of the current drawn by it from the SLT port. However, all types and
brands of SLT instruments may not uniformly draw the same minimum current; some may draw lesser and
some may draw more, making OFF-Hook detection difficult for VISIONPRO. To resolve this, VISIONPRO
provides for programmable values for threshold current for OFF-Hook detection: 10mA, 12mA, 14mA,
16mA and 18mA.
By default, the value of the Minimum Current for OFF-Hook detection is set to 12mA. Change this value
according to the current drawn by your SLT instrument.
When an SLT instrument draws current equal to or greater than the programmed threshold value of current
for OFF-Hook detection, VISIONPRO will consider the SLT instrument as OFF-Hook and will offer Dial
tone to the SLT.
• ON-Hook Detection Current (mA) or lower: VISIONPRO detects ON-Hook state of an SLT instrument to
route calls on the basis of the current drawn by it from the SLT port. However, as all types and brands of
SLT instruments may not uniformly draw the same current, ON-Hook detection becomes difficult for the
system.
To resolve this, VISIONPRO provides programmable values of threshold current for ON-Hook Detection:
10mA, 12mA, 14mA, 16mA and 18mA. By default, the value of the ON-Hook Detection Current is set to
10mA.
When an SLT instrument draws current equal to or lower than the programmed threshold value of current
for ON-Hook detection, VISIONPRO will consider the SLT instrument as ON-Hook.
39 Matrix VISIONPRO System Manual