
3170-avs.ib.rev5.doc
page 7 of 16
16/10/2007
Signal path:
Video path: (See diagrams 803142 sheet 1.)
The incoming video signal on each of inputs 1 - 5 is connected to a BNC connector on the rear assembly. These
terminals are terminated either via a termination resistor (R 1 to R 4) or via other equipment connected to the
output. The switching arrangement of the relay contacts ensures that one input is always connected to the output and
so only four termination resistors are required.
It should be noted that during relay switching a discontinuity in termination will occur, which can cause a "glitch"
in the output signal.
It should also be noted that the signal is directly coupled through the relays and so will pass any DC content present.
Care should be taken to ensure that any DC present on the signal does not exceed the contact rating of the relays.
In the event of power loss all relays revert to the power off status shown on the schematic, with input 1 connected to
the output.
The circuit arrangement for the relays provides a changeover function from one input to the next. This results in
only four relays and relay drivers being required.
The relay drivers consist of an NPN transistor pull down switch connected to the +12 Vdc rail (Q 2, 4, 6 & 8)
operating a PNP transistor pull-up of the relay coil to the +12 Vdc rail. The other side of the relay is connected to
the -12 Vdc rail to equalise loading of the +ve and -ve supply rails.
Internal adjustments
The AVS-3170 contains no user adjustable controls other than link settings described in the
Configuration
section
of this manual.
Configuration
The AVS-3170 may be used in a stand-alone mode (with a CPS-3050 local control panel) or may be connected to
external control.
The control system is the same as is used on IRT's other 3000 series switchers and the AVS-3170 may be
incorporated into complex switching systems using a combination of these modules.
These switchers include:
AVS-3011
5 x 1 analogue video
AAS-3021
5 x 1 analogue audio
DDS-3031
5 x 1 RS422
DVS-3041
5 x 1 SDI or ASI digital
In addition the following control panels may be used:
CPS-3050
local 5 button control panel (fits to front of switcher)
CPS-9001
remote 5 button control panel
CPS-1050
10 button 1 RU remote control panel
CPS-1052
20 button 1 RU remote control panel
And the following logic controllers:
CDC-3060
microprocessor programmed controller and RS232 interface
CDC-3061
3 way priority controller
CDC-3062
4 way priority controller
Some of the above switchers and controllers are normally configured for greater than 5 x 1 operation.
For details on extended operation see
Switcher set-ups larger than 5 x 1
following.