Twisted-Pair Connections - GE KTD-405 User Manual

Twisted-pair connections

The twisted-pair connections are available to connect additional devices or for existing installations where
individual wires were used to connect to the old phone-style I/O box. Easy-to-use RJ-cable connections are
also available on the new I/O box. See
Adhere to all installation guidelines while making connections, including your local codes and those provided
in Installation guidelines
Figure 8. Wire connections to the I/O box
Tie-wrap
For safety, use a tie-wrap
to secure the power cable
to the tie-in.
12 VDC power
(12 VDC transformer must
have a positive center
polarity plug
)
Earth ground (to ground)
RS-485 connection*
RS-422 IN (from keypad or
alarm unit, if used)
RS-422 OUT (to switcher
or cameras)
Speaker/shield (to remote
speaker, if used)
* For mux, DVMRe, or additional keypad I/O box. (RS-485
connections are also available with the RJ45 connectors.)
RJ-cable connections
on page 8.
Bias switch
The bias switch maintains an appropriate load on the RS-485 line. Set the bias switch to ON for one
keypad in a typical system (any one keypad and only one keypad). If your system is divided into
groups that are separated by fiber or Ethernet bridges, you must set the bias switch to ON for one
keypad in each group.
on page 12.
Chapter 2
Installation
Observe polarity for:
• 12 VDC
• RS-422
• RS-485
13