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FEATURES
The SRM-5AC, Asynchronous Short
Range Modem, is used for local data distribution, connecting full or
half duplex asynchronous DTEs to DTEs operating over unconditioned
4-wire lines (two twisted pairs). SRM-5AC ensures integrity of data
transmission for distances up to 6.8 km (4.1 miles), depending on wire
gauge.
- SRM-5AC is equipped with an internal filter
for high noise immunity. The internal filter overcomes both radiated
and conducted interference, and is recommended for noisy
environments, such as industrial locations.
- SRM-5AC features a switch-selectable DTE/DCE
interface, and a switch-selectable Printer Support Mode. It also
features strap selection for carrier constantly on or controlled
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- When set to DCE, the modem carrier can be
strapped to be constantly on, or controlled by the RTS signal
(Circuit 105). Operation with controlled carrier enables
connection of SRM-5AC in a multipoint configuration. Controlled
carrier can also be used in applications requiring passing of a
control signal end-to-end (RTS on one SRM-5AC is passed to DCD on
the other unit). SRM-5AC also contains a LED to indicate carrier
detection.
- When set to DTE, SRM-5AC operates as a DTE
for connection to DCE (such as a multiplexer port), without the
use of a cross cable.
- When set to Printer Support Mode, SRM-5AC
supports printer flow control by transmitting DTR on the printer
side (busy signal) to CTS on the other side. As a result, CTS at
the computer side will drop when the printer becomes busy.
- Innovative circuitry allows SRM-5AC to
operate without connection to the mains supply by using ultra-low
power from the data and control signals. The modem will operate even
if only TD (Circuit 103), RD (Circuit 104) and RTS (Circuit 105) are
connected.
- The low transmit level minimizes cross talk
onto adjacent circuits within the same cable. Data is transmitted
and received using a balanced interface, ensuring high immunity to
circuit noise.
- SRM-5AC is coupled to the line through
isolation transformers, which, in conjunction with additional
circuitry, protect against AC or DC overvoltages. As the
transformers are rated at over 1,500V RMS, the modem is suitable for
connection to local circuits provided by most national telephone
administrations.
- Two connectors are available for connection
to the line: a five-screw terminal block, and a modular socket for
either RJ-12 or RJ-45 (see Ordering).
Note: RJ-12 is an RJ-11 connector with Pins 1 and 6
grounded.
- SRM-5AC is fully compatible with SRM-6AC and
SRM-6ACU. Additionally, it is compatible with CMN-C6AC and CMN-C6ACU
cards for mounting in the
CMN-16 modem rack.
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SPECIFICATIONS
- Asynchronous, full or half duplex
- Data rates up to 19.2 kbps
- Point-to-point or multipoint
- Transmission range up to 6.8 km(4.1 miles)
- DCE/DTE mode
- Transformer isolated
- No AC power required
- Internal filter for high noise immunity and for
surge protection
- LED indicator for carrier detection
SRM-5AC/*/+
Asynchronous Short Range Modem
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Specify:
F for female 25-pin connector
M for male 25-pin connector |
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Specify line interface:
RJ-12 for RJ-12 jack and terminal block
RJ-45 for RJ-45 jack and terminal block
(Default is terminal block and RJ-45 connector) |
ORDERING
SRM5AC/F/RJ11
SRM5AC/F/RJ45
SRM5AC/F/RJ45/SI
SRM5AC/M/RJ11
SRM5AC/M/RJ45
SRM5AC/M/RJ45/SI
APPLICATIONS
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