SECTION б - INSTALLATION
TRANSMITTER
Several signals are available out of the Model 16, not all of which may be
required for every installation. The choice of which signals to use will
depend upon the type of transmitter used and whether or not the transmitter
must be shared with another paging terminal.
Diagrams of typical transmitter wiring connections follow the signal
descriptions below.
Digital Data
During digital paging this signal supplies the actual digital
information waveform. It is necessary to preserve the integrity of
this signal in order to assure accurate paging. For local connection
the cable length should be kept as short as possible. Pin 9 of J2
provides an RS-232 signal.
The digital data signal may be inverted through programming.
Push-to-Talk Relay (PTT)
The PTT (Push to Talk) relay closes whenever the Model 16 begins
transmit mode and remains closed until transmission is finished. The
front panel LED "Transmit" is lit whenever the PTT relay is
closed. The PTT relay closes for a period before any digital
paging signals appear; this Key Up Delay is programmable from 0 to 25
seconds in 1/10 of a second increments. The relay is supplied with 1
set of SPST contacts. J2 pins 11 and 10 are PTT common and PTT
normally open.
Request to Transmit (Request & Request 2)
These outputs are dedicated to providing a Request to Transmit signal for
shared transmitter installations. These outputs go low for a period
before the PTT relay is activated and remain low until the
completion of paging when PTT releases. The Request Hold time is
programmable from 0 to 25 seconds in 1/10 of a second increments.
Typically one of these outputs would connect to the "Busy" input
of another paging terminal, thus preventing it from trying to page
while the Model 16 is using the transmitter. If, after the Model 16
closes the Request to Transmit relay, a Busy inhibit is received
(either Channel Busy or Terminal Busy), the Model 16 will wait until
the inhibit has stopped for the programmed Channel Busy time before
keying PTT. The Request output provides an RS-232C compatible signal
and the Request 2 output provides a TTL compatible signal. Request is
taken from J2, pin 8, and Request 2 is taken from J2, pin 12.
Terminal Busy (Busy In)
This input is dedicated as an indicator that another paging terminal
has control of the transmitter. The usual source for this signal will
be the PTT closure signal or the Request output from the other paging
terminal. A "Busy" indication at either this input or the Channel Busy
(COR) input will cause transmission from the Model 16 will be
inhibited. The sense of the signal that indicates "Busy" is determined
by programming.
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