Kramer Electronics Ltd.
The Kramer VS-55 series switchers may be rack-mounted in a standard 19” (1 or 2U) EIA rack assembly,
using a special Adapter (RK-50R - 1U or a 2U model) and a mounting bracket (see section 4.1). They can
also be table mounted using their rubber feet or the provided mounting brackets. These devices do not
require any specific spacing above or below the unit for ventilation. To rack mount any of the machines,
follow the installation instructions enclosed with the adaptor.
CONNECTING TO VIDEO OR AUDIO DEVICES
Video sources and output devices (such as monitors or recorders) may be connected to the switchers
through the BNC connectors (VS-55V), through the RCA connectors (VS-55, VS-55A), or through the 4P
connectors (VS-55YC) located on the back of the unit. The active inputs should be terminated by the
connecting source. The output signal format should match that of the input signal format, (e.g.: if
Composite video is input, then Composite video is output.) The signals supported by the various models
are video, s-video, RGB/YUV and audio signals.
USING THE SWITCHERS
Connection and controlling the Switchers
1. Connect all inputs of the "VS-55" family switcher to the sources to be switched, taking care to use
the right high quality cables. If linking is needed, interconnect the "linked" units with a DB9 male-
to-male flat cable. Use video cables for video, audio cables for audio, etc. Use of the wrong cable
will impair output quality.
2. Connect the output of the "VS-55" type switcher to the input(s) of the acceptor, again using high
quality cables, turn on all units - sources, acceptors and the "VS-55" units, and you are ready to go.
3. If there no video signal is connected to input #1, then the VS-55V and VS-55YC units operate as
electronic switchers without Vertical Interval switching.
4. If you would like to extend the number of switched inputs, say forming a 10x1switcher, it can only
be done by using two machines of the same type, e.g., two VS-55Vs or two VS-55YCs, etc. In order
to do so, you should connect both EXT connectors to each other using a screened cable (an audio
cable will do the job well). Then connect outputs of both machines to each other using a "T"
connector. The combined output should then be connected to your acceptor. The concept of
operation is as following: the machines "sense" each other's status via the EXT connector, and when
a certain machine "senses" that the other is active, it shuts off it's own output circuitry, so in every
given instance, only one machine is actively connected to the acceptor.
5. The cables leading from the combined output to the acceptor's input and between the outputs of the
"VS-55" linked machines should be as short as possible.
6. Connect the "VS-55" machines to an appropriate 12 V DC source, observing correct polarity (center
pin is positive).
7. Turn on the sources, The "VS-55" switcher(s) and the acceptors.
8. If you have connected two or more machines via the EXT connector, when turning on the system,
sometimes a random combination of switches may light. Press any of the switches on any of the
interconnected "VS-55" units and the system will reset.
The VS-55 family allows remote controlling the switcher(s) using the LINK connector. Connect a
DB9 male plug with 9 wires leading from it to the remote location. A momentary touch of one of the
relevant pins (see table 1) to the common VCC pin (pin no. 8) forces the switcher to activate the