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MTM-20 (V.24 OR RS-530, AC POWER)
RAD DATA COMMUNICATIONS
MTM-20 (V.24 OR RS-530, AC POWER)
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Card Type
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Modem (synchronous)
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Chipset
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Unidentified
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Transfer Rate
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32/64Kbps
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Data Modulation
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QAM
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Data Bus
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Serial
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CONNECTIONS
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Function
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Label
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Function
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Label
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AC power in
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CN1
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Analog loopback test switch
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SW2
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V.24 or RS-530 serial port (depends on model)
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CN2
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Remote digital loopback test switch
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SW3
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Line out (see pinout below)
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SC1
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Test pattern switch
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SW4
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Local digital loopback test switch
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SW1
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Note:Modem can be made to perform self-test by holding down SW2 and SW4. The DCD, TEST, and SQ LEDs should go on, and the RD LED should go off.
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SC1 PINOUT
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Function
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Terminal
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Function
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Terminal
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Ground
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1
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Not used
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5
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Not used
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2
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Transmit line
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6
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Receive line
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3
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Transmit line
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7
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Receive line
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4
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USER CONFIGURABLE SETTINGS
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Setting
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Label
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Position
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DCD forced high
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JP3
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Pins 3 & 4 closed
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DCD normal
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JP3
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Pins 1 & 2 closed
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Signal ground connected to chassis ground
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JP4
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Pins 1 & 2 closed
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Signal ground not connected to chassis ground
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JP4
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Pins 2 & 3 closed
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Line speed set to 64Kbps
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SW5
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Position 4
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Line speed set to 32Kbps
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SW5
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Position 3
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TRANSMIT LEVEL
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Setting
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JP5/A
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JP5/B
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JP5/C
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JP5/D
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JP5/E
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0dBm
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Closed
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Open
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Open
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Open
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Open
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-3dBm
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Open
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Closed
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Open
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Open
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Open
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-6dBm
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Open
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Open
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Closed
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Open
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Open
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-9dBm
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Open
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Open
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Open
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Closed
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Open
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-12dBm
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Open
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Open
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Open
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Open
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Closed
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CLOCK SOURCE
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Setting
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JP1
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Internal
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Pins 1 & 2 closed
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External
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Pins 3 & 4 closed
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Received
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Pins 5 & 6 closed
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LINE LENGTH
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Setting
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JP2
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0-10Km
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Pins 3 & 4 closed
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7-13Km
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Pins 1 & 2 closed
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Auto select (not yet implemented)
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Pins 5 & 6 closed
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DIAGNOSTIC LED(S)
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LED
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Color
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Status
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Condition
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PWR
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Green
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On
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Power is on
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PWR
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Green
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Off
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Power is off
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RTS
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Yellow
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On
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RTS signal is high
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RTS
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Yellow
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Off
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RTS signal is low
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TD
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Yellow
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On
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DSU is transmitting SPACE
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TD
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Yellow
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Off
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DSU is not transmitting
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TD
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Yellow
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Blinking
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DSU is transmitting data
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RD
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Yellow
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On
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DSU is receiving SPACE
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RD
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Yellow
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Off
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DSU is not receiving
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RD
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Yellow
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Blinking
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DSU is receiving data
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DCD
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Yellow
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On
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Carrier signal detected
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DCD
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Yellow
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Off
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Carrier signal not detected
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TEST
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Red
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On
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DSU is in test mode
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TEST
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Red
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Off
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DSU is not in test mode
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SQ
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Yellow
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On
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Signal quality is good
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SQ
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Yellow
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Blinking
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Signal quality is poor or test pattern contains errors
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