AT&T PARTNER Installation And Use Manual page 101

– Emergency Phone. A standard phone, rather than a system
phone, should be used as an emergency phone. Do not connect
an emergency phone to extension 10 or 16 to keep them available
for power failure use.
– Auxiliary Equipment. There are a variety of ways to set up fax
machines, modems, answering machines, and credit card scanners to
work with the system. See Chapter 4 for advice on setting up this
equipment. To connect a telephone and a standard device on the
same extension, see "Combination Extensions" later in this appendix.
In-Range Out-of-Building (IROB) Protectors. Whenever phones are
installed in another building, but on the same continuous property, you
must install AT&T IROB 503A1 protectors, which provide coverage over a
distance of 3,000 feet (915 meters) for standard phones and 1,000 feet
(305 meters) for system phones. System phones require one protector in
the building where the system modules are installed and a second in the
building where the phone is installed. Standard phones require one
protector.
Off-Premises Range Extender (OPRE) allows you to connect a standard
touch-tone phone beyond 3000 feet (915 meters) in another building on
the same continuous property. It also allows you to use a special circuit
from your local phone company to provide off-premises station capability.
Limitations for Standard Devices
You can connect a standard device to your system, regardless of the
manufacturer. However, the following limitations apply:
It must be industry standard and non-proprietary. That is, it cannot be
made specifically for use on a particular telephone system. (For
example, you cannot connect an AT&T MERLIN® phone because it is
designed for use on a MERLIN system.)
Its Ringer Equivalence Number (REN*) cannot be greater than 2.0. (The
REN is shown on a label on the device, usually on the bottom.)
In addition to industry-standard equipment, you can connect a variety of other
devices—see Chapter 1. Follow the instructions provided with the equipment
for installation and use.
Combination Extensions
You can connect a standard device (such as a standard phone or an answering
machine) on an extension by itself, or so that it shares an extension with another
piece of equipment (either another standard device or a system phone). An
extension with two devices connected to it is called a combination extension.
You cannot install two system phones on the same extension, and the combined
REN (Ringer Equivalence Number) of two devices on one extension cannot
exceed 2.0. (The REN for a system phone is 0.0.)
*
REN is a measure of the power it takes to ring a phone. A typical home phone line can handle 4.0-5.0 RENs;
each extension jack in your system can handle 2.0 RENs.
C-6 Installation