ECD » Sharing
Devices » DMM-4DC
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DMM-4DC
DIGITAL
MIXING MODULE
Internal -48 VDC power
supply
RS-232 Port Sharing Device
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FEATURES/BENEFITS
- * Interface - EIA
RS-232, CCITT V.24, DB-25 Female Connectors
-
- * Data Rates -
Synchronous or Asynchronous to 128Kbps
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- * Anti-Streaming
- Automatic or Manual for unattended Circuit Restoral
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- * DCE/DTE Selectable
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- * Tail Circuit
Buffer
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- * Supports
CSU/DSU's, Lease Line Modems, Dial Modems and Terminals
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- * RTS/CTS delays
options
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- * Transparent to
Data
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- * Fully Cascadable
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- * Internal or External
Clocking
-
- * Sturdy Metal
Rackmount Enclosure
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- * -36 to -72 DC
Input
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- * Approvals UL,
CSA
and CE
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DESCRIPTION
The RS-232 Digital Mixing Module
(DMM-4DC) is a network expansion device for modem sharing or port sharing
applications in polled or contention environments. The DMM-4DC allows
up to four devices to share a modem / DSU or computer port. The port contention
modes are RTS, DCD or switch on Data. Any combination of terminals and
modems may be used in a network environment. Each port of the DMM-4DC
may be selected as a DCE or DTE interface. Once installed, system and
network efficiency are increased through higher host processor utilization
coupled with the significant decrease in idle time between host / terminal
traffic sessions.
Ideal for either synchronous or asynchronous network environments, the
DMM-4DC is protocol transparent at data rates up to 128Kbps. The DMM-4DC
may be configured to provide clocking for the entire network. To prevent
data transmission errors caused by clock differentials throughout a synchronous
network, a 8 bit ring buffer is provided for re-synchronization. In applications
where the master port and the selected port provide their own clocks,
data is clocked into the buffer at the receive clock rate of the active
port and clocked out using the master port transmit clock.
In applications where the Clear To Send (CTS) control signal is not provided
by the master port, an option for forced CTS is available via 3-position
stick headers. Additionally, several user defined RTS/CTS delay settings
are available.
The DMM-4DC also provides optional Anti-Streaming circuitry. Once enabled,
Anti-Streaming will automatically remove a defective terminal or modem
from service if the Data / Control criteria is present for the user predefined
selection period.
The DMM-4DC is housed in a sturdy aluminum standalone or rackmount enclosure.
The unit is equipped with an internal -48 VDC power supply and will provide
in excess of 315,419 hours of reliable service. All RS-232 data ports
and the power supply have surge protection that utilizes Sidactors.
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SPECIFICATIONS
Application
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Multiple
Sync/Async DCE/DTE devices operating in a polled or contention environment,
to share one DCE/DTE port
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Capacity
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Main
Input: One RS-232 Port Subchannel Ports: One to Four RS-232 Sync/Async
devices
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Interface
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EIA
RS-232-D, CCITT V.24 using DB-25 female connectors, selectable as
DCE or DTE interface
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Data
Rates
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Internal
Select: 450bps to 76.8Kbps External: Up to 128Kbps
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Data
Format
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Data
transparent at all data rates
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Timing
Options
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Internal
External: via Input Master Port
External: Telco Timing via Port 1
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Anti-Streaming
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Automatic:
Selectable time-out intervals
Disable: Selectable via dip switch
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Terminal
Service Modes
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Sequential
scanning for RTS or DCD control signal, option for switch on RXD
Data(JP6-JP9)
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Clear
To Send
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Allows normal
RTS/CTS handshaking or has option for Forced CTS on Ports 1-4 (JP1-JP4)
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RTS
To CTS Delay
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Selectable
RTS to CTS delays of 0, 5, 10 and 20ms
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Front
Panel
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Indicators:
Power, Transmit Data, Receive
Data, Channel Active, Channel Stream
Switches: Enable/Disable of each Sub-channel
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Power
Source
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DC
Voltage, Input Range of -36 to -72vdc Current Draw at 48vdc: 75ma
@ 3.6watts
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Safety
Approvals
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C-UL
60950, CE Safety EN60950 and CE EMC EN300-386-2
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MTBF
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315,419 hours
Telecordia Issue 1
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Environmental
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Operating
Temperature:
32º to 122º F (0ºto 50º C)
Relative Humidity:
5 to 95% Non-Condensing
Altitude: 0 to 10,000 feet
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Dimensions
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DMM-4DC
Height: 1.75 inches (4.44 cm)
Width: 17.00 inches (43.18 cm)
Length: 9.00 inches (22.86 cm)
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Weight
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4.5
pounds (2.1Kg)
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Warranty
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Three
Years, Return To Factory
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Ordering
Information
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Part
Number: 162000
Model: DMM-4DC
Description: RS-232 Digital Mixing Module
Included with each unit:
1) Operations Manual
2) Rackmount Kit
Optional Accessories
315ma Fuse, Qty (2) Part # 714004 |
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