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MTM-20 (G.703 RJ-45, DC POWER)

RAD DATA COMMUNICATIONS

MTM-20 (G.703 RJ-45, DC POWER)

Card Type

Modem (synchronous)

Chipset

Unidentified

Transfer Rate

32/64Kbps

Data Modulation

QAM

Data Bus

Serial

CONNECTIONS

Function

Label

Function

Label

DC power in

CN1

Analog loopback test switch

SW2

G.703 port (see pinout below)

CN2

Remote digital loopback test switch

SW3

Line out (see pinout below)

SC1

Test pattern switch

SW4

Local digital loopback test switch

SW1

   

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.

CN2 PINOUT

Function

Terminal

Function

Terminal

Not used

1

Transmit line

5

Not used

2

Receive line

6

Receive line

3

Not used

7

Transmit line

4

Not used

8

SC1 PINOUT

Function

Terminal

Function

Terminal

Ground

1

Not used

5

Not used

2

Transmit line

6

Receive line

3

Transmit line

7

Receive line

4

   

USER CONFIGURABLE SETTINGS

Setting

Label

Position

í DCD forced high

JP3

Pins 3 & 4 closed

DCD normal

JP3

Pins 1 & 2 closed

í Signal ground connected to chassis ground

JP4

Pins 1 & 2 closed

Signal ground not connected to chassis ground

JP4

Pins 2 & 3 closed

FIFO connected to transmit line

JP6

Pins 1 & 2 closed

FIFO connected to receive line

JP6

Pins 2 & 3 closd

í Line speed set to 64Kbps

SW5

Position 4

Line speed set to 32Kbps

SW5

Position 3

TRANSMIT LEVEL

Setting

JP5/A

JP5/B

JP5/C

JP5/D

JP5/E

í 0dBm

Closed

Open

Open

Open

Open

-3dBm

Open

Closed

Open

Open

Open

-6dBm

Open

Open

Closed

Open

Open

-9dBm

Open

Open

Open

Closed

Open

-12dBm

Open

Open

Open

Open

Closed

CLOCK SOURCE

Setting

JP1

í Internal

Pins 1 & 2 closed

External

Pins 3 & 4 closed

Received

Pins 5 & 6 closed

LINE LENGTH

Setting

JP2

í 0-10Km

Pins 3 & 4 closed

7-13Km

Pins 1 & 2 closed

Auto select (not yet implemented)

Pins 5 & 6 closed

DIAGNOSTIC LED(S)

LED

Color

Status

Condition

PWR

Green

On

Power is on

PWR

Green

Off

Power is off

RTS

Yellow

On

RTS signal is high

RTS

Yellow

Off

RTS signal is low

TD

Yellow

On

DSU is transmitting SPACE

TD

Yellow

Off

DSU is not transmitting

TD

Yellow

Blinking

DSU is transmitting data

RD

Yellow

On

DSU is receiving SPACE

RD

Yellow

Off

DSU is not receiving

RD

Yellow

Blinking

DSU is receiving data

DCD

Yellow

On

Carrier signal detected

DCD

Yellow

Off

Carrier signal not detected

TEST

Red

On

DSU is in test mode

TEST

Red

Off

DSU is not in test mode

SQ

Yellow

On

Signal quality is good

SQ

Yellow

Blinking

Signal quality is poor or test pattern contains errors