6
4.3
Video Inputs and Looping Outputs
For each of the 4 or 8 channels there are two BNC
connectors on the rear panel. One of these connectors is to
be used as a video input while the other connector may be
used as a looping output. It does not matter which
connector is used as the input and which is used as the
looping output. Each pair of BNCs provide an automatic
termination function that applies a 75 ohm load to the
incoming video signal when the cable is connected to either
jack. When “loop-through” operation is desired, the second
cable connection automatically unterminates the input
providing the required high impedance for “loop-through”
operation. The jacks act as automatic switches. The looping
video outputs are provided to supply video to other video
equipment. When looping, the last piece of equipment on
the video line should be terminated
4.4
Monitor Output
The monitor outputs are designed for a 75 ohm load.
Therefore if you loop the monitor output cable through
multiple monitors or their accessories, be sure their
terminations are set to Hi-Z. Only the last unit on the line
should have its termination set to 75 ohm.
LTC 5104 Series: A single monitor output permits
switched camera video through this connection.
LTC 5108 Series: These switchers may be used with one
or two monitors depending on system requirements. See
Operating Mode section and Typical Installation
illustration.
4.5
Alarm Inputs and Output
(Accessory Output)
A cable with a connector is supplied to connect alarm
closures or other accessories to the switcher.
The alarm inputs can be triggered by either a contact closure
selectable (normally open or close) (e.g., switch or relay) to
ground or by a logic ground (e.g., motion detector output).
The alarm output creates a short between the two output
pins when an alarm occurs and open-circuits the pins when
no alarms are active (triggered). The alarm output has a
maximum carrying current of 1 A and a maximum switching
voltage of 40 V AC/DC. The alarm output can be used to
signal a VCR, lamp, or relay.
CAUTION: Do not apply external voltages to
the alarm inputs. Use only isolated closures.
Precautions should be taken particularly on
long runs, to prevent pickup of spurious
signals from associated wiring which may give
false inputs or damage the switcher.
4.6
Programming System Setup
Configuration options are provided through on-screen
menus. These menus are accessed by using the DWELL key.
With video present on the monitor, a momentary press and
release of the DWELL key will gain easy access to the Dwell
Time Menu (see Screen 1).
Screen 1
The remaining configuration menus (8 for LTC 5104 Series
and 9 for the LTC 5108 Series) are also accessed with the
DWELL key. With video present on the monitor, press and
hold the DWELL key for 1 second; the monitor will display
Screen 2.
Screen 2
To advance through these 7 or 8 menus, press the
RUN/next key. When the last menu is displayed, the
RUN/next key will automatically exit the configuration mode.
The configuration mode will also exit automatically if there is
no activity for 60 seconds. Use the DWELL key again to exit
the configuration mode immediately. Any changes made
during configuration are acknowledged regardless of how the
configuration mode is exited.
