User Manual

KTD-405/KTD-405A/KTD-405-2D Controller Keypad
User Manual
8
Installation guidelines
Plan your system’s camera and device assignments before installing the system. To help plan your system, use
the System planning chart on page 69. And when installing your KTD-405 keypad, follow these guidelines:
• Each keypad requires its own I/O box. You can connect multiple I/O boxes to each other (using the
RS485 control signals) to establish multiple keypads for controlling one system. For systems that are
more complicated than are diagrammed in these instructions, contact GE Technical Support for
assistance. (See Contacting us on page 56.)
• The keypad will not support hooking all connections at once to all keypads in a network. I.E. a installer
can not connect the RS485 and RS422 ports to each keypad I/O box like a daisy chain. The keypad can
support only one network back bone at a time, either all keypads connected to RS485 with external
RS422 devices connected to the RS422 or a RS422 back bone with RS485 devices connected to the
individual RS485.
• The audio and speaker connections are used only with a KTD-405A.
• Observe polarity when installing the RS-422 and RS-485 cables as well as the 12 VDC power supply
(if you are not using the provided transformer with positive polarity center plug).
• The keypad itself is not grounded.
• Grounding the I/O box is optional, but it does provide some additional protection against equipment
damage due to power surges caused by electrical storms.
• There must be no current in the shield of shielded cables. Maintain an open circuit (noncontinuous
path) for the shield and hold it at the earth ground potential by grounding it at only one location.
• You can connect the RS-485 shield of individual cable segments to each other, but to nothing else. You
will still ground the resulting shield circuit at one location only, despite the number of shield junctions.
• Each electrical circuit (RS-485 segment) must be biased. If keypads reside on separate electrical
circuits (separated by fiber or Ethernet bridges, for example), then more than one keypad might have
the bias switch set to ON (one for each circuit).
• The bias is sensitive to the polarity of the 12 VDC supply. If polarity on the power line is reversed, the
keypad will not be damaged, but biasing will not operate correctly.
• Each electrical segment being terminated must be terminated at each end with bias turned on at one
location only. Termination is generally required for the first and last device on a longer line. The
termination switches are located within or on the devices themselves (keypads and cameras). Refer to
the devices’ manuals for termination requirements and methods.
• An electrical segment for biasing and termination considerations may consist of several wire runs and
devices. For example, in Figure 65 on page 60 there is only one electrical segment even though there
are several pieces of wire and several devices.
• The installation of the KTD-405 is designed to work at the head end of a RS422 Digiplex or a RS485
GE/Impac system, so care should be taken to keep only one RS485 network and one RS422 network in
a large system. The RS422 network must be made into a Digiplex wheel or loop to properly support
RS422 serial Alarm annunciation and clearing.