ALM
N
O
C
O
M
N
C
R
M
T
BTSC
COMPOSITE
BASE BAND
LOOP THRU
BTSC
COMPOSITE
STEREO
SAP
PRO
I NPUTS
IN (XMT)
OUT (RCV)
MONITOR
INPUT
OUTPUT
FIGURE 2-2 455 Rear Panel
2-10. Remote Control Interface Information.
The 455 remote control input is capable of switching the unit to an alternate configuration which
the user has pre-programmed (see Section 3-4 for set-up information). The alternate configuration
can differ from the normal configuration in any or all of the parameters which can be set using
the front panel switches (ON/OFF, Frequency, WIDE/NARROW Deviation).
The remote input has a 10k
Ω
nominal internal pull-up resistor to +5V. An input of less than +2V
selects REMOTE, and an input of greater than +3V selects LOCAL. Because of the internal pull-
up resistor, an open circuit condition also selects LOCAL. The connecting circuit should be
capable of sinking at least -200µA to assure a logical low condition to select remote. Most
commercial logic devices (including TTL & CMOS) are compatible with this input.
CAUTION
Do not exceed the following maximum ratings for the remote control input:
MAXIMUM INPUT VOLTAGE: +60 VDC
MINIMUM INPUT VOLTAGE: -60 VDC
Although the remote input has excellent high frequency noise immunity due to an internal filter,
low frequency noise on long lines may cause inadvertent switching. Shielded cables are
recommended for all applications, or, if long distances or high noise environments are
expected, balanced line drivers and receivers should be used.
2-11. VIDEO BASEBAND CONNECTIONS.
Video baseband connections are BNC connectors on the rear of the shelf. A detailed description
of the connections are:
Transmitter:
Input - Video input from video source. If video is not used this port should be terminated with
455 Operation Manual
Page 14
6/23/98
