Studio Technologies ISS - Manual (Page 8)

ISS User Guide Issue 3, June 1990
Studio Technologies, Inc. Page 9
ISS
transformer, but does not contain internal
transformers, external transformers can
be added. Refer to the Technical Notes
section of this manual for recommended
transformers.
Connecting the Remote Control Signals
Provision has been made for remotely
controlling a number of ISS functions.
These signals interface with the ISS via a
25-pin male D-type connector located on
the back panel. In most cases, the ISS will
be located some distance from the TV
master control point. It may be desirable to
control the ISS’s operation using a telem-
etry system or switches connected via cable
pairs. The following is a description of the
remote control inputs:
Remote Control Enable: Activating this
allows use of the Remote Simulate from
Left and Remote Simulate from Right com-
mands. Activating the Remote Control
Enable will override the commands from the
Recognition Card.
Remote Simulate from Left: This command
is only active when Remote Control Enable
is in effect. Remote Simulate from Left
allows you to place the ISS in the simulate
from the left channel mode.
Remote Simulate from Right: This command
is only active when Remote Control Enable
is in effect. Remote Simulate from Right
allows you to place the ISS in the simulate
from the right channel mode.
Remote I/O Bypass: Activating this com-
mand forces the relays on the Transfer
Relay Assembly to release, connecting the
audio input signals directly to the audio
output connectors. This electrically takes
the ISS out of the audio path.
Remote Polarity Correction Function
Disable: Activating this command disables
the polarity correction function.
Low voltage, current limited logic type
signals are required for remote control
operation. Continuous or pulse (momen-
tary) signals can be used. These logic
signals are usually nominally 5 or 12Vdc.
LED based optical couplers, located on the
ISS circuit cards, are utilized to eliminate
interfacing problems. The couplers require
current, rather than voltage or a contact
closure, to operate. The minimum current
required is 4mA; the maximum is 20mA. For
protection, 680 ohm resistors, located on
the ISS circuit boards, are in series with the
optical couplers. These resistors limit a
5Vdc signal to 4.5mA, and limit a 12Vdc
signal to 13mA. If higher DC voltages are
used, additional current limiting resistors,
connected in series with the remote control
inputs, are required. Failure to provide
current limiting will damage and/or shorten
the life of the opto couplers.
Connecting to the Status Relay Outputs
Relay contacts indicating several ISS oper-
ating characteristics are provided for user-
designated functions. These contacts are
accessible via the 25-pin male D-type con-
nector located on the back panel. These
can be extremely useful for local or remote
monitoring. An automation system can
watch for an error condition, or a master
control operator can monitor ISS operation
through a set of indicator lights. Dry (iso-
lated) relay contacts are provided so that
virtually any monitoring scheme can be
implemented without interfering with ISS
operation due to ground loops, noise
pickup, etc. The following gives a descrip-
tion of the Status Relay Outputs.