Switch S1-6: Front Panel Switch Enable/Disable

Switch S1-6 determines whether the front panel switches may be used to perform diagnostic functions.

S1-6

Activation

Description

Off

Enabled

Front panel switches may be used

 

 

to activate/terminate diagnostics

On

Disabled

Front panel switches will have no

 

 

effect on operation of the unit

Switch S1-7: DTE Loop Request Line Enable/Disable

The setting for switch S1-7 determines whether the DTE signals can be used to activate/terminate the loopback diagnostic modes and BER test patterns.

 

DTE TM Line

 

S1-7

Activation

Description

Off

Enabled

DTE Loop request line switches

 

 

may be used to activate/terminate

 

 

diagnostics.

On

Disabled

DTE loop request lines will

 

 

have no effect on operation of

 

 

the unit.

Switch S1-8: Receive RDL Enable/Disable

Switch S1-8 determines whether or not the unit will respond to loop requests from the remote device.

S1-6

Activation

Description

Off

Enabled

Unit wil respond to loop requests

 

 

from the remote device.

On

Disabled

Unit wil ignore loop requests from

 

 

the remote device.

4.0 INSTALLATION

The Model 2450 is designed for 4-wire, full duplex communication over a DDS or Clear Channel carrier circuit, or over dedicated twisted pair. This section will describe proper connection of the line interface, the DTE (terminal) interface, and the AC power supply.

4.1 LINE (NETWORK) CONNECTION

The RJ-48S port on a Model 2450 CSU/DSU is prewired for a standard TELCO wiring environment (see Figure 4, below). Connect this port to the RJ-48S jack provided by your digital service carrier using a straight through twisted pair cable between 19 and 26 AWG. To be sure you have the right wiring, use the table below as a guide.

 

1

(TX+)

1

2

(TX-)

3

(N/C)

2

3

4

(N/C)

4

5

(N/C)

5

6

6

(N/C)

7

8

7

(RX+)

 

8

(RX-)

Figure 4. Interface pinouts for Model 2450 RJ-48S jack.

4.1.1 CONNECTING OVER PRIVATE TWISTED PAIR

If you are using a pair of Model 2450s as short range modems over private twisted pair, make the connection between them using a twisted pair crossover cable pinned according to the diagram below.

 

RJ-48S Cable (4-Wire)

 

SIGNAL

PIN#

PIN#

SIGNAL

TX+

1-----------------------

7

RX+

TX-

2-----------------------

8

RX-

RX+

7-----------------------

1

TX+

RX-

8-----------------------

2

TX-

7

8

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Image 5
Patton electronic 2450 user manual Line Network Connection, Connecting Over Private Twisted Pair, Signal PIN#