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SHM-768K
6. SHM-768K 19" Rack Version
6.1 Description
The Rack (part number RM110A) shown in Figures 6-1 and 6-2 consists of a
power supply and up to 14 plug-in card modems. The rear panel consists of
fourteen five-screw terminal blocks (TB1) and fourteen connectors (J1). The
terminal block (TB1) provides five screws for connecting the transmit and
receive lines. The transmit pair is connected to the terminals marked XMT,
and the receive pair is connected to the terminals marked RCV. A nut for
optional ground connection is supplied at the left side of the rear panel.
The interface connector (J1) is a 25-pin female connector, which provides
all digital interface signals (refer to Table 6-1 for pinout). Optional CIA/V.35
or CIA/X.21 interface adapters provide two V.35 or X.21 connectors for any
two adjacent cards.
6.2 Card Modem
The SHM-768K (Card) short-range modems, part number ME280C-35 and
ME280C-530, are card versions of the SHM-768K. Indicator LEDs and test
push-buttons of each ME280C are conveniently located on the front panel
for clear visibility and easy handling.
6.3 Power Supply
The power supply accepts either 115 or 230 VAC according to the stated
rated voltage of the unit. It consists of a power-line transformer, fuse, and
an operating switch. All power-regulating circuitry is located on the card
modems. Each card has two fuses which protect the entire system against
power failure due to a short circuit in one card. Primary power needed is
115/230 VAC ±10%, 47 to 63 Hz, at 24 VA maximum.
AC power should be supplied through a 5-ft (1.5-m) standard power cable
between the AC mains socket at the rear of the power supply module and a
standard, grounded, easily accessible AC outlet. An integral fuse is located
in the AC mains socket of the power supply.
