Section 4. Installation
4-4
SERIAL CRT INTERFACE
The requirements for serial interface to the encoder are listed in Table 4.
INSTALLATION-
1
. Configure the terminal's serial communications parameters to match. Check jumper JP-14
on the PCB to find the baud rate.
Table 4. INSTALLATION-1. Serial Communications Parameters
Baud rate
300, 600, 1200, 2400, 4800 or 9600
Data bits
8
Stop bits
1
Parity bits
none
Handshake
none
Duplex
full
It may be necessary to install additional jumper wires across the terminal's serial port
hardware hand-shaking pins (CTS/RTS, DTR/DSR) to enable communications. Consult the
CRT or computer manuals to determine if the hardware hand-shaking requirements can be
disabled internally.
INTERFACE CONNECTOR
Connections between the encoder and the radio equipment are made on the terminal strip
TB1 inside the encoder. Connections on both terminal strips are described in Table 4.
INSTALLATION-2
or Table 4. INSTALLATION-3.
Table 4. INSTALLATION-2. Connector TB1 Pin-out
TB1-#
Signal
Function
1
AC/DC In
12 VAC wall transformer or +12 VDC
2
AC In
12 VAC wall transformer
3
Audio Out
(not used)
4
Switched Audio Out
Audio for paging
5
Ground
Common ground
6
Switched Mic Input
Microphone input for voice paging
7
Channel Busy
Inhibit page-out when channel is in-use. Usually
connected to receiver's squelch signal.
8
Digital Mode
Digital/Audio output indicator
9
Digital Data
Data for digital paging
10
PTT Normally Open
PTT relay for transmitter control
11
PTT Common
PTT relay for transmitter control
12
PTT Normally Closed
PTT relay for transmitter control
